<PAGE> PAGE 1
000 A000000 04/30/98
000 C000000 0000894242
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 A
001 A000000 BLACKROCK INVESTMENT QUALITY MUN. TRUST INC.
001 B000000 811-7354
001 C000000 8002277236
002 A000000 345 PARK AVENUE
002 B000000 NEW YORK
002 C000000 NY
002 D010000 10154
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 BLACKROCK FINANCIAL MANAGEMENT, INC.
008 B000001 A
008 C000001 801-32183
008 D010001 NEW YORK
008 D020001 NY
008 D030001 10154
010 A000001 PRINCETON ADMINISTRATORS, L.P.
010 C010001 PRINCETON
010 C020001 NJ
010 C030001 08543
010 C040001 9095
011 A000001 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
011 B000001 8-7221
011 C010001 NEW YORK
011 C020001 NY
011 C030001 10281
011 A000002 A.G. EDWARDS & SONS, INC.
011 B000002 8-13580
011 C010002 ST. LOUIS
<PAGE> PAGE 2
011 C020002 MO
011 C030002 63103
011 A000003 KIDDER, PEABODY & CO. INCORPORATED
011 B000003 8-4831
011 C010003 NEW YORK
011 C020003 NY
011 C030003 10005
011 A000004 PAINEWEBBER INCORPORATED
011 B000004 8-16267
011 C010004 NEW YORK
011 C020004 NY
011 C030004 10019
011 A000005 SHEARSON LEHMAN BROTHERS INC.
011 B000005 8-12324
011 C010005 NEW YORK
011 C020005 NY
011 C030005 10285
011 A000006 ADVEST, INC.
011 B000006 8-21409
011 C010006 HARTFORD
011 C020006 CT
011 C030006 06103
011 A000007 DAIN BOSWORTH INCORPORATED
011 B000007 8-3259
011 C010007 MINNEAPOLIS
011 C020007 MN
011 C030007 55402
011 A000008 FIRST ALBANY CORPORATION
011 B000008 8-2018
011 C010008 ALBANY
011 C020008 NY
011 C030008 12207
011 A000009 THE ROBINSON-HUMPHREY COMPANY, INC.
011 B000009 8-27190
011 C010009 ATLANTA
011 C020009 GA
011 C030009 30326
011 A000010 WEDBUSH MORGAN SECURITIES
011 B000010 8-12987
011 C010010 LOS ANGELES
011 C020010 CA
011 C030010 90030
011 A000011 KEMPER SECURITIES, INC.
011 B000011 8-37180
011 C010011 CHICAGO
011 C020011 IL
011 C030011 60603
011 A000012 LEGG MASON WOOD WALKER, INCORPORATED
011 B000012 8-15939
011 C010012 BALTIMORE
011 C020012 MD
<PAGE> PAGE 3
011 C030012 21202
011 A000013 GRUNTAL & CO. INCORPORATED
011 B000013 8-31022
011 C010013 NEW YORK
011 C020013 NY
011 C030013 10005
011 A000014 MORGAN KEEGAN & COMPANY, INC.
011 B000014 8-15001
011 C010014 MEMPHIS
011 C020014 TN
011 C030014 38103
012 A000001 STATE STREET BANK AND TRUST COMPANY
012 B000001 85-05003
012 C010001 NORTH QUINCY
012 C020001 MA
012 C030001 02171
012 A000002 BANKERS TRUST COMPANY
012 B000002 84-0
012 C010002 NEW YORK
012 C020002 NY
012 C030002 10006
013 A000001 DELOITTE & TOUCHE LLP
013 B010001 NEW YORK
013 B020001 NY
013 B030001 10281
013 B040001 1434
014 A000001 PNC SECURITIES CORP.
014 B000001 8-000
015 A000001 STATE STREET BANK AND TRUST COMPANY
015 B000001 C
015 C010001 NORTH QUINCY
015 C020001 MA
015 C030001 02171
015 E010001 X
018 000000 N
019 A000000 Y
019 B000000 21
019 C000000 BLACKROCKX
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
020 C000010 0
021 000000 0
022 A000001 GOLDMAN, SACHS & CO.
022 B000001 13-5108880
<PAGE> PAGE 4
022 C000001 27244
022 D000001 30125
022 A000002 PAINEWEBBER INCORPORATED
022 B000002 13-2638166
022 C000002 38706
022 D000002 3930
022 A000003 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
022 B000003 13-5674085
022 C000003 17679
022 D000003 12833
022 A000004 MORGAN (J.P.) SECURITIES INC.
022 B000004 13-3224016
022 C000004 12794
022 D000004 13044
022 A000005 GMS GROUP, L.L.C. (THE)
022 B000005 13-2982938
022 C000005 0
022 D000005 10216
022 A000006 FIRST ALBANY CORPORATION
022 B000006 14-1391446
022 C000006 8734
022 D000006 1365
022 A000007 LEHMAN BROTHERS INC.
022 B000007 13-2518466
022 C000007 587
022 D000007 8655
022 A000008 CIBC OPPENHEIMER CORP.
022 B000008 13-2798343
022 C000008 2538
022 D000008 5290
022 A000009 MORGAN STANLEY & CO. INCORPORATED
022 B000009 13-2655998
022 C000009 7321
022 D000009 0
022 A000010 PERSHING DIV. OF DONALDSON, LUFKIN & JENRETTE
022 B000010 13-2741729
022 C000010 4013
022 D000010 0
023 C000000 120194
023 D000000 90841
024 000000 N
026 A000000 N
026 B000000 Y
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 N
<PAGE> PAGE 5
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.350
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 Y
054 N000000 N
055 A000000 N
055 B000000 N
056 000000 N
057 000000 N
058 A000000 N
059 000000 Y
<PAGE> PAGE 6
060 A000000 Y
060 B000000 Y
061 000000 0
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 0.0
062 E000000 1.9
062 F000000 0.0
062 G000000 0.0
062 H000000 0.0
062 I000000 0.0
062 J000000 0.0
062 K000000 0.0
062 L000000 0.0
062 M000000 0.0
062 N000000 0.0
062 O000000 148.6
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 0
063 B000000 20.0
064 A000000 Y
064 B000000 N
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 N
070 B010000 N
070 B020000 N
070 C010000 Y
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 Y
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 Y
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 N
070 K010000 Y
<PAGE> PAGE 7
070 K020000 N
070 L010000 N
070 L020000 N
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 Y
070 R020000 N
071 A000000 84779
071 B000000 90841
071 C000000 382734
071 D000000 22
072 A000000 6
072 B000000 10136
072 C000000 0
072 D000000 0
072 E000000 0
072 F000000 674
072 G000000 289
072 H000000 0
072 I000000 192
072 J000000 52
072 K000000 0
072 L000000 31
072 M000000 29
072 N000000 0
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 17
072 S000000 3
072 T000000 0
072 U000000 0
072 V000000 0
072 W000000 70
072 X000000 1357
072 Y000000 0
072 Z000000 8779
072AA000000 2370
072BB000000 119
072CC010000 0
072CC020000 216
072DD010000 8193
072DD020000 0
<PAGE> PAGE 8
072EE000000 4445
073 A010000 0.3938
073 A020000 0.0000
073 B000000 0.1988
073 C000000 0.0000
074 A000000 15
074 B000000 0
074 C000000 4810
074 D000000 377640
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 5576
074 K000000 0
074 L000000 6509
074 M000000 20
074 N000000 394570
074 O000000 10032
074 P000000 112
074 Q000000 0
074 R010000 0
074 R020000 0
074 R030000 0
074 R040000 325
074 S000000 130000
074 T000000 254101
074 U010000 16707
074 U020000 0
074 V010000 15.21
074 V020000 0.00
074 W000000 0.0000
074 X000000 10604
074 Y000000 0
075 A000000 0
075 B000000 257350
076 000000 13.81
077 A000000 N
078 000000 N
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
<PAGE> PAGE 9
086 F020000 0
087 A010000 COMMON
087 A020000 09247D6
087 A030000 BKN
087 B010000 PREFERRED SERIES T28
087 B020000 09247D303
087 C010000 PREFERRED SERIES T7
087 C020000 09247D204
088 A000000 N
088 B000000 N
088 C000000 N
088 D000000 Y
SIGNATURE KATHY HONER
TITLE ACCOUNTING MANAGER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000894242
<NAME> THE BLACKROCK INVESTMENT QUALITY MUNICIPAL TRUST INC.
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> OCT-31-1998
<PERIOD-START> NOV-01-1997
<PERIOD-END> APR-30-1998
<INVESTMENTS-AT-COST> 364319483
<INVESTMENTS-AT-VALUE> 382449942
<RECEIVABLES> 12085314
<ASSETS-OTHER> 34597
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 394569853
<PAYABLE-FOR-SECURITIES> 10031493
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 437226
<TOTAL-LIABILITIES> 10468719
<SENIOR-EQUITY> 130000000
<PAID-IN-CAPITAL-COMMON> 232244836
<SHARES-COMMON-STOCK> 16707093
<SHARES-COMMON-PRIOR> 16707093
<ACCUMULATED-NII-CURRENT> 1556139
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 2169700
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 18130459
<NET-ASSETS> 384101134
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 10135982
<OTHER-INCOME> 0
<EXPENSES-NET> (1356977)
<NET-INVESTMENT-INCOME> 8779005
<REALIZED-GAINS-CURRENT> 2250913
<APPREC-INCREASE-CURRENT> (215997)
<NET-CHANGE-FROM-OPS> 10813921
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (8193051)
<DISTRIBUTIONS-OF-GAINS> (4445453)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 0
<NUMBER-OF-SHARES-REDEEMED> 0
<SHARES-REINVESTED> 0
<NET-CHANGE-IN-ASSETS> (1824583)
<ACCUMULATED-NII-PRIOR> 970185
<ACCUMULATED-GAINS-PRIOR> 4364240
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 674147
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1356977
<AVERAGE-NET-ASSETS> 257349646
<PER-SHARE-NAV-BEGIN> 15.32
<PER-SHARE-NII> .53
<PER-SHARE-GAIN-APPREC> .12
<PER-SHARE-DIVIDEND> (.39)
<PER-SHARE-DISTRIBUTIONS> (.20)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 15.21
<EXPENSE-RATIO> 1.06
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
