UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM N-Q QUARTERLY SCHEDULE OF PORTFOLIO HOLDINGS OF REGISTERED MANAGEMENT INVESTMENT COMPANY Investment Company Act File number 811-21348 Name of Fund: BlackRock Muni Intermediate Duration Fund, Inc. Fund Address: P.O. Box 9011 Princeton, NJ 08543-9011 Name and address of agent for service: Robert C. Doll, Jr., Chief Executive Officer, BlackRock Muni Intermediate Duration Fund, Inc., 800 Scudders Mill Road, Plainsboro, NJ, 08536. Mailing address: P.O. Box 9011, Princeton, NJ, 08543-9011 Registrant's telephone number, including area code: (609) 282-2800 Date of fiscal year end: 05/31/2007 Date of reporting period: 12/01/06 - 02/28/07 Item 1 - Schedule of Investments BlackRock Muni Intermediate Duration Fund, Inc. Schedule of Investments as of February 28, 2007 (in Thousands) Face State Amount Municipal Bonds Value Alabama - 3.4% $ 5,500 Jefferson County, Alabama, Limited Obligation School Warrants, Series A, 5.50% due 1/01/2021 $ 6,024 6,500 Jefferson County, Alabama, Limited Obligation School Warrants, Series A, 5.25% due 1/01/2023 6,986 6,600 Tuscaloosa, Alabama, Special Care Facilities Financing Authority, Residential Care Facility Revenue Bonds (Capstone Village, Inc. Project), Series A, 5.625% due 8/01/2025 6,677 Arizona - 2.6% 2,560 Coconino County, Arizona, Pollution Control Corporation Revenue Bonds (Arizona Public Service Co.-Navajo Project), VRDN, AMT, Series A, 3.70% due 10/01/2029 (h) 2,560 2,820 Maricopa County, Arizona, IDA, Education Revenue Bonds (Arizona Charter Schools Project 1), Series A, 6.625% due 7/01/2020 2,881 3,000 Navajo County, Arizona, IDA, IDR (Stone Container Corporation Project), AMT, 7.20% due 6/01/2027 3,075 995 Pima County, Arizona, IDA, Education Revenue Bonds (Arizona Charter Schools Project), Series C, 6.70% due 7/01/2021 1,073 1,750 Pima County, Arizona, IDA, Education Revenue Bonds (Arizona Charter Schools Project), Series K/L, 6.375% due 7/01/2031 1,898 3,630 Vistancia Community Facilities District, Arizona, GO, 5% due 7/15/2014 3,864 Arkansas - 0.7% 3,755 Conway, Arkansas, Public Facilities Board, Capital Improvement Revenue Refunding Bonds (Hendrix College Projects), Series B, 5% due 10/01/2026 3,899 California - 21.9% 5,000 California State Department of Water Resources, Power Supply Revenue Bonds, Series A, 5.375% due 5/01/2012 (g) 5,467 14,795 California State, GO, 5.50% due 4/01/2014 (g) 16,545 795 California State, GO, 5.50% due 4/01/2028 875 5,000 California State, GO, Refunding, 5.25% due 2/01/2027 (f) 5,338 10,000 California State Public Works Board, Lease Revenue Bonds (Department of Corrections), Series C, 5.50% due 6/01/2020 11,042 2,500 California Statewide Communities Development Authority, Health Facility Revenue Bonds (Memorial Health Services), Series A, 6% due 10/01/2023 2,782 2,400 Elk Grove, California, Poppy Ridge Community Facilities Number 3 Special Tax, Series 1, 6% due 9/01/2008 (g) 2,496 35,265 Los Angeles, California, Unified School District, GO, Series A, 5% due 7/01/2013 (f)(g) 38,144 10,135 Peralta, California, Community College District, GO (Election of 2000), Series D, 5% due 8/01/2030 (e) 10,843 1,515 Rowland, California, Unified School District, GO (Election of 2000), Series B, 5.25% due 8/01/2027 (e) 1,630 Portfolio Abbreviations To simplify the listings of BlackRock Muni Intermediate Duration Fund, Inc.'s portfolio holdings in the Schedule of Investments, we have abbreviated the names of many of the securities according to the list below. AMT Alternative Minimum Tax (subject to) COP Certificates of Participation EDA Economic Development Authority EDR Economic Development Revenue Bonds GO General Obligation Bonds IDA Industrial Development Authority IDB Industrial Development Board IDR Industrial Development Revenue Bonds PCR Pollution Control Revenue Bonds S/F Single-Family VRDN Variable Rate Demand Notes BlackRock Muni Intermediate Duration Fund, Inc. Schedule of Investments as of February 28, 2007 (concluded) (in Thousands) Face State Amount Municipal Bonds Value California $ 585 Sacramento, California, Special Tax (North Natomas Community Facilities), (concluded) Series 4-C, 5.60% due 9/01/2020 $ 623 1,720 Sacramento, California, Special Tax (North Natomas Community Facilities), Series 4-C, 5.75% due 9/01/2022 1,843 500 Sacramento, California, Special Tax (North Natomas Community Facilities), Series 4-C, 5.90% due 9/01/2023 539 3,000 Sacramento, California, Special Tax (North Natomas Community Facilities), Series 4-C, 6% due 9/01/2028 3,238 2,295 San Francisco, California, City and County, GO (Branch Library Facilities Improvements), Series G, 5% due 6/15/2023 (f) 2,452 3,000 San Jose, California, Airport Revenue Bonds, Series A, 5.25% due 3/01/2017 (c) 3,163 3,100 San Jose, California, GO (Libraries, Parks and Public Safety Projects), 5% due 9/01/2030 (f) 3,282 9,030 Sequoia, California, Unified High School District, GO, Refunding, Series B, 5.50% due 7/01/2035 (e) 10,204 4,875 Tamalpais, California, Union High School District, GO (Election of 2001), 5% due 8/01/2028 (e) 5,146 2,610 Tustin, California, Unified School District, Senior Lien Special Tax Bonds (Community Facilities District Number 97-1), Series A, 5% due 9/01/2032 (e) 2,730 Colorado - 2.5% 2,000 Denver, Colorado, City and County Airport Revenue Refunding Bonds, Series E, 5.25% due 11/15/2023 (f) 2,038 800 Elk Valley, Colorado, Public Improvement Revenue Bonds (Public Improvement Fee), Series A, 7.10% due 9/01/2014 857 2,250 Montrose, Colorado, Memorial Hospital, Revenue Bonds, 6.375% due 12/01/2023 2,542 7,500 Plaza Metropolitan District Number 1, Colorado, Tax Allocation Revenue Bonds (Public Improvement Fees), 7.50% due 12/01/2015 8,333 1,000 Southlands, Colorado, Medical District, GO (Metropolitan District Number 1), 6.75% due 12/01/2016 1,109 Connecticut - 1.9% 1,160 Connecticut State Development Authority, Airport Facility Revenue Bonds (Learjet Inc. Project), AMT, 7.95% due 4/01/2026 1,403 8,000 Connecticut State Development Authority, PCR, Refunding (Connecticut Light and Power Company), Series A, 5.85% due 9/01/2028 8,401 1,250 South Central Connecticut Regional Water Authority, Water System Revenue Refunding Bonds, Fifteenth, Series A, 5.125% due 8/01/2009 (c)(g) 1,304 Florida - 5.3% 2,935 Harbor Bay, Florida, Community Development District, Capital Improvement Special Assessment Bonds, 6.75% due 5/01/2034 3,220 1,085 Heritage Isle at Viera Community Development District, Florida, Special Assessment Bonds, Series B, 5% due 11/01/2009 1,084 1,900 Lee County, Florida, Hospital Board of Directors, Hospital Revenue Bonds (Memorial Health System), VRDN, Series A, 3.65% due 4/01/2025 (h) 1,900 5,500 Miami-Dade County, Florida, Aviation Revenue Refunding Bonds (Miami International Airport), AMT, 5.75% due 10/01/2019 (c) 5,972 3,500 Midtown Miami, Florida, Community Development District, Special Assessment Revenue Bonds, Series A, 6% due 5/01/2024 3,785 2,000 Midtown Miami, Florida, Community Development District, Special Assessment Revenue Bonds, Series B, 6.50% due 5/01/2037 2,216 3,670 Orange County, Florida, Health Facilities Authority, Health Care Revenue Refunding Bonds (Orlando Lutheran Towers), 5% due 7/01/2013 3,654 930 Orlando, Florida, Urban Community Development District, Capital Improvement Special Assessment Bonds, 6% due 5/01/2020 1,001 1,085 Portofino Shores, Florida, Community Development District, Special Assessment Bonds, Series A, 6.40% due 5/01/2034 1,170 2,390 South Lake County, Florida, Hospital District Revenue Bonds (South Lake Hospital Inc.), 6.625% due 10/01/2023 2,710 430 Sterling Hill, Florida, Community Development District, Capital Improvement Revenue Refunding Bonds, Series B, 5.50% due 11/01/2010 430 4,000 University of Florida Research Foundation Inc., Capital Improvement Revenue Bonds, 5.125% due 9/01/2033 (a) 4,104 Georgia - 3.1% 1,500 Atlanta, Georgia, Tax Allocation Bonds (Atlantic Station Project), 7.90% due 12/01/2024 1,667 5,395 Brunswick and Glynn County, Georgia, Development Authority, First Mortgage Revenue Bonds (Coastal Community Retirement Corporation Project), Series A, 7.125% due 1/01/2025 5,275 2,800 Brunswick and Glynn County, Georgia, Development Authority, First Mortgage Revenue Bonds (Coastal Community Retirement Corporation Project), Series A, 7.25% due 1/01/2035 2,750 4,500 Fulton County, Georgia, Residential Care Facilities, Revenue Refunding Bonds (Canterbury Court Project), Series A, 5.80% due 2/15/2018 4,576 1,245 Savannah, Georgia, EDA, First Mortgage Revenue Bonds (Marshes of Skidaway), Series A, 6.25% due 1/01/2012 1,279 2,245 Savannah, Georgia, EDA, First Mortgage Revenue Bonds (Marshes of Skidaway), Series A, 6.85% due 1/01/2019 2,416 Idaho - 0.8% 4,000 Boise City, Idaho, COP, AMT, 5.50% due 9/01/2025 (c) 4,192 370 Idaho Housing and Finance Association, S/F Mortgage Revenue Bonds, AMT, Series F-2, 5.85% due 7/01/2015 (d)(k) 376 Illinois - 3.7% 2,510 Chicago, Illinois, O'Hare International Airport Revenue Bonds, Third Lien, AMT, Series B-2, 6% due 1/01/2029 (j) 2,824 6,000 Hodgkins, Illinois, Environmental Improvement Revenue Bonds (Metro Biosolids Management LLC Project), AMT, 5.90% due 11/01/2017 6,222 6,930 Illinois, Development Finance Authority Revenue Bonds (Community Rehabilitation Providers Facilities), Series A, 6.625% due 7/01/2032 7,580 1,400 Illinois Health Facilities Authority, Revenue Refunding Bonds (University of Chicago Hospitals), VRDN, 3.64% due 8/01/2026 (f)(h) 1,400 1,800 Illinois State Finance Authority Revenue Bonds (Landing At Plymouth Place Project), Series A, 6% due 5/15/2025 1,926 1,580 Village of Wheeling, Illinois, Revenue Bonds (North Milwaukee/Lake-Cook Tax Increment Financing (TIF) Redevelopment Project), 6% due 1/01/2025 1,616 Indiana - 0.8% 4,300 Indiana Transportation Finance Authority, Highway Revenue Bonds, Series A, 5% due 6/01/2028 (e) 4,533 Louisiana - 2.2% 6,965 Louisiana Public Facilities Authority Revenue Bonds (University of New Orleans Research and Technology Foundation, Inc. - Student Housing Project), 5.25% due 3/01/2026 (f) 7,642 5,000 Port New Orleans, Louisiana, IDR, Refunding (Continental Grain Company Project), 6.50% due 1/01/2017 5,100 Maine - 0.3% 1,965 Portland, Maine, Housing Development Corporation, Senior Living Revenue Bonds (Avesta Housing Development Corporation Project), Series A, 6% due 2/01/2034 2,085 Maryland - 0.1% 500 Maryland State Industrial Development Financing Authority, EDR (Our Lady of Good Counsel School), Series A, 6% due 5/01/2035 538 Massachusetts - 4.9% 4,560 Massachusetts Bay Transportation Authority, Sales Tax Revenue Refunding Bonds, Senior Series A, 5% due 7/01/2012 (g) 4,854 7,695 Massachusetts Bay Transportation Authority, Special Assessment Revenue Refunding Bonds, Series A, 5% due 7/01/2015 (g) 8,401 1,210 Massachusetts State Development Finance Agency, Resource Recovery Revenue Bonds (Ogden Haverhill Associates), AMT, Series B, 5.35% due 12/01/2015 1,245 2,000 Massachusetts State Development Finance Agency, Resource Recovery Revenue Bonds (Ogden Haverhill Associates), AMT, Series B, 5.50% due 12/01/2019 2,076 3,000 Massachusetts State Industrial Finance Agency, Resource Recovery Revenue Refunding Bonds (Ogden Haverhill Project), AMT, Series A, 5.30% due 12/01/2009 3,078 8,325 Massachusetts State School Building Authority, Dedicated Sales Tax Revenue Bonds, Series A, 5% due 8/15/2030 (e) 8,893 Michigan - 1.3% 2,325 Macomb County, Michigan, Hospital Finance Authority, Hospital Revenue Bonds (Mount Clemens General Hospital), Series B, 5.875% due 11/15/2034 2,472 4,795 Michigan State Hospital Finance Authority, Revenue Refunding Bonds (Oakwood Obligated Group), Series A, 6% due 4/01/2022 5,290 Minnesota - 1.0% 1,000 Minneapolis and Saint Paul, Minnesota, Housing and Redevelopment Authority, Health Care System Revenue Bonds (Group Health Plan Inc. Project), 6% due 12/01/2019 1,098 2,545 Minneapolis and Saint Paul, Minnesota, Housing and Redevelopment Authority, Health Care System Revenue Bonds (Group Health Plan Inc. Project), 6% due 12/01/2021 2,798 2,000 Minnesota State Municipal Power Agency, Electric Revenue Bonds, Series A, 5.25% due 10/01/2024 2,142 Mississippi - 1.4% 5,000 Mississippi Business Finance Corporation, Mississippi, PCR, Refunding (System Energy Resources Inc. Project), 5.875% due 4/01/2022 5,054 2,910 Mississippi Business Finance Corporation, Mississippi, PCR, Refunding (System Energy Resources Inc. Project), 5.90% due 5/01/2022 2,941 Missouri - 0.4% 2,050 Missouri Development Finance Board, Cultural Facilities Revenue Bonds (Nelson Gallery Foundation), VRDN, Series B, 3.63% due 12/01/2031 (f)(h) 2,050 Nevada - 0.4% 2,245 Clark County, Nevada, Improvement District Number 142, Special Assessment Bonds, 6.375% due 8/01/2023 2,325 New Jersey - 13.5% 3,635 Garden State Preservation Trust of New Jersey, Open Space and Farmland Preservation Revenue Bonds, Series A, 5.80% due 11/01/2021 (e) 4,200 5,050 Garden State Preservation Trust of New Jersey, Open Space and Farmland Preservation Revenue Bonds, Series A, 5.80% due 11/01/2023 (e) 5,840 10,950 New Jersey EDA, Cigarette Tax Revenue Bonds, 5.625% due 6/15/2018 11,347 9,810 New Jersey EDA, Cigarette Tax Revenue Bonds, 5.75% due 6/15/2029 10,643 17,900 New Jersey EDA, Motor Vehicle Surcharge Revenue Bonds, Series A, 5.25% due 7/01/2033 (f) 19,370 5,540 New Jersey EDA, Special Facility Revenue Bonds (Continental Airlines Inc. Project), AMT, 6.625% due 9/15/2012 5,974 5,000 New Jersey EDA, Water Facilities Revenue Refunding Bonds (American Water), AMT, Series B, 5.125% due 4/01/2022 (a) 5,290 4,215 New Jersey State Transportation Trust Fund Authority, Transportation System Revenue Bonds, Series D, 5% due 6/15/2018 (a) 4,567 11,120 New Jersey State Transportation Trust Fund Authority, Transportation System Revenue Bonds, Series D, 5% due 6/15/2019 (e) 12,024 New Mexico - 3.9% 3,000 Farmington, New Mexico, PCR, Refunding (Public Service Company of New Mexico - San Juan Project), Series D, 6.375% due 4/01/2022 3,067 9,000 Farmington, New Mexico, PCR, Refunding (Tucson Electric Power Company - San Juan Project), Series A, 6.95% due 10/01/2020 9,290 9,520 New Mexico Finance Authority, Senior Lien State Transportation Revenue Bonds, Series A, 5.125% due 6/15/2018 (f) 10,336 New York - 25.8% 1,090 Dutchess County, New York, IDA, Civic Facility Revenue Bonds (Saint Francis Hospital), Series B, 7.25% due 3/01/2019 1,201 10,500 Metropolitan Transportation Authority, New York, Revenue Refunding Bonds, Series A, 5.75% due 11/15/2032 11,452 875 New York City, New York, City IDA, Civic Facility Revenue Bonds (Special Needs Facilities Pooled Program), Series C-1, 5.50% due 7/01/2007 878 3,500 New York City, New York, City IDA, Special Facility Revenue Bonds (Continental Airlines Inc. Project), AMT, 8.375% due 11/01/2016 3,913 1,110 New York City, New York, City Transitional Finance Authority, Future Tax Secured Revenue Bonds, Series C, 5.50% due 5/01/2009 (g) 1,164 5,000 New York City, New York, GO, Refunding, Series B, 5.75% due 8/01/2015 5,466 2,055 New York City, New York, IDA, Civic Facility Revenue Bonds (Special Needs Facilities Pooled Program), Series C-1, 6.80% due 7/01/2019 2,206 9,070 New York City, New York, Sales Tax Asset Receivable Corporation Revenue Bonds, Series A, 5% due 10/15/2020 (f) 9,791 5,580 New York State Dormitory Authority, Lease Revenue Refunding Bonds (Court Facilities), Series A, 5.25% due 5/15/2012 5,937 4,615 New York State Dormitory Authority, Non-State Supported Debt, Revenue Refunding Bonds (Mount Sinai-NYU Medical Center Health System), Series A, 6.625% due 7/01/2010 (g) 5,088 3,670 New York State Dormitory Authority, Non-State Supported Debt, Revenue Refunding Bonds (Mount Sinai-NYU Medical Center Health System), Series A, 6.625% due 7/01/2010 (g) 4,047 2,385 New York State Dormitory Authority, Non-State Supported Debt, Revenue Refunding Bonds (Mount Sinai-NYU Medical Center Health System), Series A, 6.625% due 7/01/2018 2,575 1,330 New York State Dormitory Authority, Non-State Supported Debt, Revenue Refunding Bonds (Mount Sinai-NYU Medical Center Health System), Series A, 6.625% due 7/01/2019 1,435 1,000 New York State Dormitory Authority Revenue Bonds (North Shore L I Jewish Group), 5% due 5/01/2012 1,047 9,540 New York State Dormitory Authority Revenue Bonds (School Districts Financing Program), Series D, 5.25% due 10/01/2023 (f) 10,231 7,775 New York State Dormitory Authority, Revenue Refunding Bonds (City University System), Consolidated Second Generation, Series A, 6.125% due 7/01/2013 (a) 8,428 7,380 New York State Environmental Facilities Corporation, State Personal Income Tax Revenue Bonds, Series A, 5.25% due 12/15/2014 (c)(g) 8,180 60 New York State Thruway Authority, Local Highway and Bridge Service Contract, Revenue Refunding Bonds, 5.50% due 4/01/2017 65 825 New York State Urban Development Corporation, Correctional and Youth Facilities Services, Revenue Refunding Bonds, Series A, 5.50% due 1/01/2011 (g) 881 10,825 New York State Urban Development Corporation, Correctional and Youth Facilities Services, Revenue Refunding Bonds, Series A, 5.50% due 1/01/2017 11,480 10,000 New York State Urban Development Corporation, Personal Income Tax Revenue Bonds (State Facilities), Series A-1, 5.25% due 3/15/2034 (c) 10,816 5,000 Port Authority of New York and New Jersey, Senior Consolidated Revenue Bonds, AMT, 131st Series, 5% due 12/15/2017 (b) 5,323 3,340 Tobacco Settlement Financing Corporation of New York Revenue Bonds, Series A-1, 5.50% due 6/01/2016 3,521 6,510 Tobacco Settlement Financing Corporation of New York Revenue Bonds, Series A-1, 5.25% due 6/01/2022 (a) 6,971 9,750 Tobacco Settlement Financing Corporation of New York Revenue Bonds, Series C-1, 5.50% due 6/01/2020 (c) 10,608 7,000 Tobacco Settlement Financing Corporation of New York Revenue Bonds, Series C-1, 5.50% due 6/01/2021 7,612 10,000 Tobacco Settlement Financing Corporation of New York Revenue Bonds, Series C-1, 5.50% due 6/01/2022 10,863 North Carolina - 1.7% 3,105 Gaston County, North Carolina, Industrial Facilities and Pollution Control Financing Authority, Revenue Bonds (National Gypsum Company Project), AMT, 5.75% due 8/01/2035 3,346 6,000 North Carolina Medical Care Commission, Health Care Facilities, First Mortgage Revenue Refunding Bonds (Presbyterian Homes Project), 7% due 10/01/2010 (g) 6,717 Ohio - 0.2% 1,280 Port of Greater Cincinnati Development Authority, Ohio, Special Assessment Revenue Bonds (Cooperative Public Parking Infrastructure Project), 6.30% due 2/15/2024 1,389 Pennsylvania - 6.4% 3,500 Montgomery County, Pennsylvania, IDA, Revenue Bonds (Whitemarsh Continuing Care Project), 6% due 2/01/2021 3,698 7,710 Pennsylvania Economic Development Financing Authority, Exempt Facilities Revenue Bonds (National Gypsum Company), AMT, Series A, 6.25% due 11/01/2027 8,122 7,490 Philadelphia, Pennsylvania, Gas Works Revenue Refunding Bonds, 1975 General Ordinance, 17th Series, 5.375% due 7/01/2022 (e) 8,136 9,630 Pittsburgh, Pennsylvania, GO, Refunding, Series B, 5.25% due 9/01/2017 (e) 10,701 1,750 Sayre, Pennsylvania, Health Care Facilities Authority, Revenue Refunding Bonds (Guthrie Healthcare System), Series A, 6.25% due 12/01/2015 1,930 3,000 Sayre, Pennsylvania, Health Care Facilities Authority, Revenue Refunding Bonds (Guthrie Healthcare System), Series A, 6.25% due 12/01/2016 3,309 1,490 Sayre, Pennsylvania, Health Care Facilities Authority, Revenue Refunding Bonds (Guthrie Healthcare System), Series A, 6.25% due 12/01/2018 1,640 South Carolina - 2.2% 8,000 Georgetown County, South Carolina, Pollution Control Facilities, Revenue Refunding Bonds (International Paper Company Project), Series A, 5.125% due 2/01/2012 8,335 4,250 Medical University Hospital Authority, South Carolina, FHA-Insured Mortgage Hospital Facilities, Revenue Refunding Bonds, Series A, 5.25% due 8/15/2023 (d)(f)(k) 4,593 Tennessee - 4.9% 300 Blount County, Tennessee, Public Building Authority, Local Government Public Improvement Revenue Bonds, VRDN, Series A3A, 3.64% due 6/01/2026 (a)(h) 300 1,800 Johnson City, Tennessee, Health and Educational Facilities Board, Retirement Facility Revenue Bonds (Appalachian Christian Village Project), Series A, 6% due 2/15/2019 1,827 5,000 McMinn County, Tennessee, IDB, PCR (Calhoun Newsprint Co. Project), AMT, 7.625% due 3/01/2016 5,027 2,005 Memphis-Shelby County, Tennessee, Airport Authority, Airport Revenue Bonds, AMT, Series A, 5.50% due 3/01/2017 (e) 2,117 4,000 Sevier County, Tennessee, Public Building Authority, Local Government Public Improvement Revenue Bonds, VRDN, Series IV-F-1, 3.64% due 6/01/2025 (a)(h) 4,000 3,550 Shelby County, Tennessee, Health, Educational & Housing Facilities Board Revenue Bonds (Germantown Village), Series A, 6.75% due 12/01/2018 3,513 1,450 Shelby County, Tennessee, Health, Educational & Housing Facilities Board Revenue Bonds (Germantown Village), Series A, 7% due 12/01/2023 1,458 745 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6% due 9/01/2012 (g) 831 1,495 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6% due 9/01/2012 (g) 1,667 1,255 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6% due 9/01/2012 (g) 1,400 2,505 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6% due 9/01/2012 (g) 2,794 1,310 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6.25% due 9/01/2012 (g) 1,477 2,190 Shelby County, Tennessee, Health, Educational and Housing Facility Board, Hospital Revenue Refunding Bonds (Methodist Healthcare), 6.25% due 9/01/2012 (g) 2,469 Texas - 12.0% 6,230 Austin, Texas, Convention Center Revenue Bonds (Convention Enterprises Inc.), First Tier, Series A, 6.375% due 1/01/2011 (g) 6,751 10,260 Austin, Texas, Convention Center Revenue Bonds (Convention Enterprises Inc.), First Tier, Series A, 6.70% due 1/01/2011 (g) 11,344 500 Bell County, Texas, Health Facilities Development Corporation, Hospital Revenue Bonds (Scott & White Memorial Hospital), VRDN, Series B-2, 3.64% due 8/15/2029 (f)(h) 500 1,500 Bexar County, Texas, Health Facilities Development Corporation, Revenue Refunding Bonds (Army Retirement Residence Project), 6.30% due 7/01/2012 (g) 1,693 1,500 Brazos River Authority, Texas, PCR, Refunding (TXU Energy Company LLC Project), AMT, Series A, 6.75% due 4/01/2038 1,637 5,085 Brazos River Authority, Texas, PCR, Refunding (Texas Utility Company), AMT, Series A, 7.70% due 4/01/2033 5,839 4,000 Dallas-Fort Worth, Texas, International Airport Facility Improvement Corporation, Revenue Bonds (Learjet Inc.), AMT, Series A-1, 6.15% due 1/01/2016 4,041 5,000 Dallas-Fort Worth, Texas, International Airport Facility Improvement Corporation, Revenue Refunding Bonds, AMT, Series A-2, 9% due 5/01/2029 6,227 2,440 Gulf Coast, Texas, IDA, Solid Waste Disposal Revenue Bonds (Citgo Petroleum Corporation Project), AMT, 7.50% due 5/01/2025 2,750 3,000 Gulf Coast Waste Disposal Authority, Texas, Revenue Refunding Bonds (International Paper Company), AMT, Series A, 6.10% due 8/01/2024 3,239 5,790 Houston, Texas, Airport System Revenue Refunding Bonds, Sub-Lien, AMT, Series A, 5.50% due 7/01/2023 (e) 6,050 1,500 Houston, Texas, Health Facilities Development Corporation, Retirement Facility Revenue Bonds (Buckingham Senior Living Community), Series A, 7% due 2/15/2023 1,683 7,420 Lower Colorado River Authority, Texas, PCR (Samsung Austin Semiconductor), AMT, 6.95% due 4/01/2030 8,077 2,600 Matagorda County, Texas, Navigation District Number 1, Revenue Refunding Bonds (Reliant Energy Inc.), Series C, 8% due 5/01/2029 2,741 2,300 Port Corpus Christi, Texas, Individual Development Corporation, Environmental Facilities Revenue Bonds (Citgo Petroleum Corporation Project), AMT, 8.25% due 11/01/2031 2,358 5,000 Sabine River Authority, Texas, PCR, Refunding (TXU Electric Company Project/TXU Energy Company LLC), AMT, Series B, 5.75% due 5/01/2030 5,156 Utah - 0.2% 900 Emery County, Utah, PCR, Refunding (PacifiCorp Projects), VRDN, 3.64% due 11/01/2024 (a)(h) 900 Virginia - 4.5% 3,285 James City County, Virginia, IDA, Residential Care Facility Revenue Refunding Bonds, Series A, 5.75% due 3/01/2017 3,453 1,150 James City County, Virginia, IDA, Residential Care Facility Revenue Refunding Bonds, Series A, 6% due 3/01/2023 1,228 2,250 Loudoun County, Virginia, IDA, IDR, Refunding (Dulles Airport Marriott Hotel), 7.125% due 9/01/2015 2,275 10,735 Pocahontas Parkway Association, Virginia, Toll Road Revenue Bonds, Senior-Series A, 5.50% due 8/15/2008 (g) 11,225 7,800 Tobacco Settlement Financing Corporation of Virginia, Asset-Backed Revenue Bonds, 5.625% due 6/01/2037 8,330 Washington - 2.1% 1,500 Seattle, Washington, Municipal Light and Power Revenue Bonds, 5.30% due 12/01/2020 (f) 1,579 10,000 Snohomish County, Washington, School District Number 015 (Edmonds), GO, 5% due 12/01/2019 (c) 10,856 Guam - 0.8% 4,250 Commonwealth of the Northern Mariana Islands, Guam, GO, Series A, 6.75% due 10/01/2033 4,767 Puerto Rico - 7.7% 1,820 Puerto Rico Commonwealth, Public Improvement, GO, Refunding, Series B, 5.25% due 7/01/2032 1,977 17,935 Puerto Rico Electric Power Authority, Power Revenue Bonds, Series NN, 5.50% due 7/01/2018 19,463 5,390 Puerto Rico Industrial, Medical and Environmental Pollution Control Facilities Financing Authority, Special Facilities Revenue Bonds (American Airlines Inc.), Series A, 6.45% due 12/01/2025 5,502 5,170 Puerto Rico Public Buildings Authority, Government Facilities Revenue Refunding Bonds, Series D, 5.25% due 7/01/2027 5,473 8,000 Puerto Rico Public Buildings Authority, Government Facilities Revenue Refunding Bonds, Series I, 5.50% due 7/01/2021 8,810 3,535 Puerto Rico Public Finance Corporation, Commonwealth Appropriation Revenue Bonds, Series E, 5.50% due 8/01/2029 3,741 U.S. Virgin 1,860 Virgin Islands Government Refinery Facilities, Revenue Refunding Bonds (Hovensa Islands - 1.6% Coker Project), AMT, 6.50% due 7/01/2021 2,104 6,750 Virgin Islands Public Finance Authority, Refinery Facilities Revenue Bonds (Hovensa Refinery), AMT, 6.125% due 7/01/2022 7,503 Total Municipal Bonds (Cost - $814,809) - 146.2% 856,461 Municipal Bonds Held in Trust (I) California - 3.2% 17,730 California Pollution Control Financing Authority, PCR, Refunding (Pacific Gas and Electric), AMT, Series A, 5.35% due 12/01/2016 (f) 18,996 New York - 2.1% 11,100 New York City, New York, Sales Tax Asset Receivable Corporation Revenue Bonds, Series A, 5.25% due 10/15/2027 (a) 12,157 Texas - 5.6% 31,240 Harris County, Texas, Toll Road Revenue Refunding Bonds, Senior Lien, Series A, 5.25% due 8/15/2035 (e) 32,581 Total Municipal Bonds Held in Trust (Cost - $63,151) - 10.9% 63,734 Total Investments (Cost - $877,960*) - 157.1% 920,195 Other Assets Less Liabilities - 2.7% 15,896 Liability for Trust Certificates, Including Interest Expense Payable - (5.1%) (30,212) Preferred Stock, at Redemption Value - (54.7%) (320,194) ----------- Net Assets Applicable to Common Stock - 100.0% $ 585,685 =========== * The cost and unrealized appreciation (depreciation) of investments as of February 28, 2007, as computed for federal income tax purposes, were as follows: Aggregate cost $ 848,384 ==================== Gross unrealized appreciation $ 42,216 Gross unrealized depreciation (440) -------------------- Net unrealized appreciation $ 41,776 ==================== (a) AMBAC Insured. (b) CIFG Insured. (c) FGIC Insured. (d) FHA Insured. (e) FSA Insured. (f) MBIA Insured. (g) Prerefunded. (h) Security may have a maturity of more than one year at time of issuance, but has variable rate and demand features that qualify it as a short-term security. The rate disclosed is that currently in effect. This rate changes periodically based upon prevailing market rates. (i) Securities represent underlying bonds transferred to a separate securitization trust established in a tender option bond transaction in which the Fund may have acquired the residual interest certificates. These securities serve as collateral in a financing transaction. (j) XL Capital Insured. (k) Federal Housing Administration/Veterans' Administration Mortgages packaged by the Federal National Mortgage Association. Item 2 - Controls and Procedures 2(a) - The registrant's certifying officers have reasonably designed such disclosure controls and procedures to ensure material information relating to the registrant is made known to us by others particularly during the period in which this report is being prepared. The registrant's certifying officers have determined that the registrant's disclosure controls and procedures are effective based on our evaluation of these controls and procedures as of a date within 90 days prior to the filing date of this report. 2(b) - As of September 29, 2006, with the conclusion of the combination of Merrill Lynch's asset management business with BlackRock, the registrant was migrated to BlackRock's trading and compliance monitoring systems, and various personnel changes occurred. In conjunction with these business improvements, there were no changes in the registrant's internal control over financial reporting (as defined in Rule 30a-3(d) under Act (17 CFR 270.30a-3(d)) that occurred during the last fiscal quarter that has materially affected, or is reasonably likely to affect, the registrant's internal control over financial reporting. Item 3 - Exhibits Certifications - Attached hereto Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized. BlackRock Muni Intermediate Duration Fund, Inc. By: /s/ Robert C. Doll, Jr. ----------------------- Robert C. Doll, Jr. Chief Executive Officer BlackRock Muni Intermediate Duration Fund, Inc. Date: April 23, 2007 Pursuant to the requirements of the Securities Exchange Act of 1934 and the Investment Company Act of 1940, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the dates indicated. By: /s/ Robert C. Doll, Jr. ----------------------- Robert C. Doll, Jr. Chief Executive Officer BlackRock Muni Intermediate Duration Fund, Inc. Date: April 23, 2007 By: /s/ Donald C. Burke ------------------- Donald C. Burke Chief Financial Officer BlackRock Muni Intermediate Duration Fund, Inc. Date: April 23, 2007