<PAGE> PAGE 1
000 A000000 12/31/96
000 C000000 0000225635
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 MERRILL LYNCH MUNICIPAL BOND FUND, INC.
001 B000000 811-2688
001 C000000 6092822800
002 A000000 P.O. BOX 9011
002 B000000 PRINCETON
002 C000000 NJ
002 D010000 08543
002 D020000 9011
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 Y
007 B000000 3
007 C010100 1
007 C020100 NATIONAL PORTFOLIO
007 C030100 N
007 C010200 2
007 C020200 INSURED PORTFOLIO
007 C030200 N
007 C010300 3
007 C020300 LIMITED MATURITY PORTFOLIO
007 C030300 N
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A00AA01 FUND ASSET MANAGEMENT, L.P.
008 B00AA01 A
008 C00AA01 801-12485
008 D01AA01 PRINCETON
008 D02AA01 NJ
008 D03AA01 08543
008 D04AA01 9011
011 A00AA01 MERRILL LYNCH FUNDS DISTRIBUTOR, INC.
011 B00AA01 8-14663
011 C01AA01 PRINCETON
011 C02AA01 NJ
011 C03AA01 08543
<PAGE> PAGE 2
011 C04AA01 9011
012 A00AA01 MERRILL LYNCH FINANCIAL DATA SERVICES, INC.
012 B00AA01 84-01339
012 C01AA01 JACKSONVILLE
012 C02AA01 FL
012 C03AA01 32246
012 C04AA01 6484
013 A00AA01 DELOITTE & TOUCHE LLP
013 B01AA01 PRINCETON
013 B02AA01 NJ
013 B03AA01 08540
014 A00AA01 MERRILL LYNCH, PIERCE, FENNER & SMITH INC.
014 B00AA01 8-7221
015 A00AA01 THE BANK OF NEW YORK
015 B00AA01 C
015 C01AA01 NEW YORK
015 C02AA01 NY
015 C03AA01 10286
015 E01AA01 X
015 A00AA02 BANKERS TRUST COMPANY
015 B00AA02 S
015 C01AA02 NEW YORK
015 C02AA02 NY
015 C03AA02 10006
015 E01AA02 X
015 A00AA03 CHEMICAL BANK
015 B00AA03 S
015 C01AA03 NEW YORK
015 C02AA03 NY
015 C03AA03 10017
015 E01AA03 X
015 A00AA04 CUSTODIAL TRUST CO.
015 B00AA04 S
015 C01AA04 NEW YORK
015 C02AA04 NY
015 C03AA04 10167
015 E01AA04 X
015 A00AA05 MORGAN GUARANTEE TRUST CO.
015 B00AA05 S
015 C01AA05 NEW YORK
015 C02AA05 NY
015 C03AA05 10260
015 E01AA05 X
018 00AA00 Y
019 A00AA00 Y
019 B00AA00 184
019 C00AA00 MERRILLLYN
020 A000001 SMITH BARNEY INC.
020 B000001 13-1912900
020 C000001 17
020 C000002 0
<PAGE> PAGE 3
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 17
022 A000001 SMITH BARNEY INC.
022 B000001 13-1912900
022 C000001 368279
022 D000001 362472
022 A000002 GOLDMAN, SACHS & CO.
022 B000002 13-5108880
022 C000002 276693
022 D000002 317025
022 A000003 MORGAN ( J.P.) SECURITIES INC.
022 B000003 13-3224016
022 C000003 294890
022 D000003 273368
022 A000004 PAINEWEBBER INCORPORATED
022 B000004 13-2638166
022 C000004 196797
022 D000004 214641
022 A000005 DILLON, READ & CO. INC.
022 B000005 13-1939216
022 C000005 149188
022 D000005 250645
022 A000006 MORGAN STANLEY & CO. INCORPORATED
022 B000006 13-2655998
022 C000006 200210
022 D000006 143091
022 A000007 LEHMAN BROTHERS INC.
022 B000007 13-2518466
022 C000007 128967
022 D000007 129707
022 A000008 BT SECURITIES CORPORATION
022 C000008 129644
022 D000008 124239
022 A000009 OPPENHEIMER & CO., INC.
022 B000009 13-2798343
022 C000009 115679
022 D000009 87281
022 A000010 BEAR, STEARNS & CO. INC.
022 B000010 13-3299429
022 C000010 77614
022 D000010 110727
023 C000000 2611397
023 D000000 2681913
024 00AA00 N
<PAGE> PAGE 4
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 Y
037 00AA00 N
038 00AA00 0
039 00AA00 N
040 00AA00 Y
041 00AA00 Y
049 00AA00 N
050 00AA00 N
051 00AA00 N
052 00AA00 N
053 A00AA00 N
054 A00AA00 Y
054 B00AA00 Y
054 C00AA00 N
054 D00AA00 N
054 E00AA00 N
054 F00AA00 N
054 G00AA00 N
054 H00AA00 Y
054 I00AA00 N
054 J00AA00 Y
054 K00AA00 N
054 L00AA00 N
054 M00AA00 Y
054 N00AA00 N
058 A00AA00 N
059 00AA00 Y
060 A00AA00 Y
060 B00AA00 Y
061 00AA00 0
066 A00AA00 N
067 00AA00 N
068 A00AA00 N
068 B00AA00 N
069 00AA00 N
077 A000000 Y
077 O000000 Y
078 000000 N
028 A010100 11516
028 A020100 3030
028 A030100 0
028 A040100 25918
<PAGE> PAGE 5
028 B010100 14046
028 B020100 3716
028 B030100 0
028 B040100 19776
028 C010100 14670
028 C020100 2986
028 C030100 0
028 C040100 18071
028 D010100 17294
028 D020100 2958
028 D030100 0
028 D040100 23978
028 E010100 10797
028 E020100 3639
028 E030100 0
028 E040100 22161
028 F010100 21878
028 F020100 3843
028 F030100 0
028 F040100 26513
028 G010100 90201
028 G020100 20172
028 G030100 0
028 G040100 136417
028 H000100 45353
029 000100 Y
030 A000100 136
030 B000100 4.00
030 C000100 0.00
031 A000100 13
031 B000100 0
032 000100 0
033 000100 123
034 000100 Y
035 000100 309
036 A000100 N
036 B000100 0
042 A000100 0
042 B000100 0
042 C000100 100
042 D000100 0
042 E000100 0
042 F000100 0
042 G000100 0
042 H000100 0
043 000100 1642
044 000100 0
045 000100 Y
046 000100 N
047 000100 Y
048 000100 0.000
<PAGE> PAGE 6
048 A010100 250000
048 A020100 0.500
048 B010100 0
048 B020100 0.000
048 C010100 0
048 C020100 0.000
048 D010100 0
048 D020100 0.000
048 E010100 0
048 E020100 0.000
048 F010100 0
048 F020100 0.000
048 G010100 0
048 G020100 0.000
048 H010100 0
048 H020100 0.000
048 I010100 0
048 I020100 0.000
048 J010100 0
048 J020100 0.000
048 K010100 250000
048 K020100 0.475
055 A000100 N
055 B000100 N
056 000100 Y
057 000100 N
062 A000100 Y
062 B000100 0.0
062 C000100 0.0
062 D000100 0.0
062 E000100 2.3
062 F000100 0.0
062 G000100 0.0
062 H000100 0.0
062 I000100 0.0
062 J000100 0.0
062 K000100 0.0
062 L000100 0.0
062 M000100 0.0
062 N000100 0.0
062 O000100 95.7
062 P000100 0.0
062 Q000100 0.0
062 R000100 0.0
063 A000100 0
063 B000100 20.5
064 A000100 Y
064 B000100 N
070 A010100 Y
070 A020100 N
070 B010100 N
<PAGE> PAGE 7
070 B020100 N
070 C010100 N
070 C020100 N
070 D010100 N
070 D020100 N
070 E010100 Y
070 E020100 Y
070 F010100 N
070 F020100 N
070 G010100 Y
070 G020100 N
070 H010100 N
070 H020100 N
070 I010100 Y
070 I020100 N
070 J010100 Y
070 J020100 N
070 K010100 N
070 K020100 N
070 L010100 N
070 L020100 N
070 M010100 N
070 M020100 N
070 N010100 N
070 N020100 N
070 O010100 Y
070 O020100 N
070 P010100 Y
070 P020100 Y
070 Q010100 N
070 Q020100 N
070 R010100 N
070 R020100 N
071 A000100 532656
071 B000100 565017
071 C000100 1372715
071 D000100 39
072 A000100 6
072 B000100 46915
072 C000100 0
072 D000100 0
072 E000100 0
072 F000100 3480
072 G000100 76
072 H000100 0
072 I000100 289
072 J000100 67
072 K000100 0
072 L000100 43
072 M000100 11
072 N000100 63
<PAGE> PAGE 8
072 O000100 0
072 P000100 0
072 Q000100 0
072 R000100 12
072 S000100 24
072 T000100 1642
072 U000100 0
072 V000100 0
072 W000100 26
072 X000100 5733
072 Y000100 0
072 Z000100 41182
072AA000100 12998
072BB000100 2922
072CC010100 20809
072CC020100 0
072DD010100 30429
072DD020100 10753
072EE000100 0
073 A010100 0.0000
073 A020100 0.0000
073 B000100 0.0000
073 C000100 0.0000
074 A000100 172
074 B000100 0
074 C000100 34173
074 D000100 1382514
074 E000100 0
074 F000100 0
074 G000100 0
074 H000100 0
074 I000100 0
074 J000100 25079
074 K000100 0
074 L000100 27355
074 M000100 50
074 N000100 1469343
074 O000100 14654
074 P000100 859
074 Q000100 0
074 R010100 0
074 R020100 0
074 R030100 0
074 R040100 8923
074 S000100 0
074 T000100 1444907
074 U010100 99540
074 U020100 40326
074 V010100 0.00
074 V020100 0.00
074 W000100 0.0000
<PAGE> PAGE 9
074 X000100 35488
074 Y000100 0
075 A000100 0
075 B000100 1440823
076 000100 0.00
028 A010200 11510
028 A020200 4421
028 A030200 0
028 A040200 43873
028 B010200 15172
028 B020200 5510
028 B030200 0
028 B040200 38217
028 C010200 13545
028 C020200 4401
028 C030200 0
028 C040200 32378
028 D010200 14161
028 D020200 4408
028 D030200 0
028 D040200 38439
028 E010200 11471
028 E020200 5440
028 E030200 0
028 E040200 35883
028 F010200 21931
028 F020200 5697
028 F030200 0
028 F040200 58822
028 G010200 87790
028 G020200 29877
028 G030200 0
028 G040200 247612
028 H000200 47298
029 000200 Y
030 A000200 141
030 B000200 4.00
030 C000200 0.00
031 A000200 17
031 B000200 0
032 000200 0
033 000200 124
034 000200 Y
035 000200 502
036 A000200 N
036 B000200 0
042 A000200 0
042 B000200 0
042 C000200 100
042 D000200 0
042 E000200 0
<PAGE> PAGE 10
042 F000200 0
042 G000200 0
042 H000200 0
043 000200 2827
044 000200 0
045 000200 Y
046 000200 N
047 000200 Y
048 000200 0.000
048 A010200 250000
048 A020200 0.400
048 B010200 1250000
048 B020200 0.375
048 C010200 0
048 C020200 0.000
048 D010200 0
048 D020200 0.000
048 E010200 0
048 E020200 0.000
048 F010200 0
048 F020200 0.000
048 G010200 0
048 G020200 0.000
048 H010200 0
048 H020200 0.000
048 I010200 0
048 I020200 0.000
048 J010200 0
048 J020200 0.000
048 K010200 1500000
048 K020200 0.350
055 A000200 N
055 B000200 N
056 000200 Y
057 000200 N
062 A000200 Y
062 B000200 0.0
062 C000200 0.0
062 D000200 0.0
062 E000200 4.2
062 F000200 0.0
062 G000200 0.0
062 H000200 0.0
062 I000200 0.0
062 J000200 0.0
062 K000200 0.0
062 L000200 0.0
062 M000200 0.0
062 N000200 0.0
062 O000200 95.2
062 P000200 0.0
<PAGE> PAGE 11
062 Q000200 0.0
062 R000200 0.0
063 A000200 0
063 B000200 20.7
064 A000200 Y
064 B000200 N
070 A010200 Y
070 A020200 N
070 B010200 N
070 B020200 N
070 C010200 N
070 C020200 N
070 D010200 N
070 D020200 N
070 E010200 N
070 E020200 N
070 F010200 N
070 F020200 N
070 G010200 N
070 G020200 N
070 H010200 N
070 H020200 N
070 I010200 N
070 I020200 N
070 J010200 Y
070 J020200 N
070 K010200 N
070 K020200 N
070 L010200 N
070 L020200 N
070 M010200 N
070 M020200 N
070 N010200 N
070 N020200 N
070 O010200 Y
070 O020200 N
070 P010200 Y
070 P020200 Y
070 Q010200 N
070 Q020200 N
070 R010200 N
070 R020200 N
071 A000200 865478
071 B000200 868398
071 C000200 2152573
071 D000200 40
072 A000200 6
072 B000200 70947
072 C000200 0
072 D000200 0
072 E000200 0
<PAGE> PAGE 12
072 F000200 4258
072 G000200 138
072 H000200 0
072 I000200 430
072 J000200 101
072 K000200 0
072 L000200 75
072 M000200 13
072 N000200 60
072 O000200 0
072 P000200 0
072 Q000200 0
072 R000200 19
072 S000200 29
072 T000200 2827
072 U000200 0
072 V000200 0
072 W000200 51
072 X000200 8001
072 Y000200 0
072 Z000200 62946
072AA000200 25150
072BB000200 5339
072CC010200 26890
072CC020200 0
072DD010200 45246
072DD020200 17700
072EE000200 0
073 A010200 0.0000
073 A020200 0.0000
073 B000200 0.0000
073 C000200 0.0000
074 A000200 144
074 B000200 0
074 C000200 96300
074 D000200 2172608
074 E000200 0
074 F000200 0
074 G000200 0
074 H000200 0
074 I000200 0
074 J000200 26200
074 K000200 0
074 L000200 43208
074 M000200 82
074 N000200 2338542
074 O000200 39513
074 P000200 1166
074 Q000200 0
074 R010200 0
074 R020200 0
<PAGE> PAGE 13
074 R030200 0
074 R040200 14475
074 S000200 0
074 T000200 2283388
074 U010200 196093
074 U020200 86877
074 V010200 0.00
074 V020200 0.00
074 W000200 0.0000
074 X000200 50829
074 Y000200 0
075 A000200 0
075 B000200 2331776
076 000200 0.00
028 A010300 8356
028 A020300 872
028 A030300 0
028 A040300 13439
028 B010300 2983
028 B020300 1087
028 B030300 0
028 B040300 11249
028 C010300 3093
028 C020300 826
028 C030300 0
028 C040300 11724
028 D010300 5214
028 D020300 837
028 D030300 0
028 D040300 13013
028 E010300 9992
028 E020300 1040
028 E030300 0
028 E040300 12049
028 F010300 5535
028 F020300 1624
028 F030300 0
028 F040300 17778
028 G010300 35173
028 G020300 6286
028 G030300 0
028 G040300 79252
028 H000300 15805
029 000300 Y
030 A000300 16
030 B000300 1.00
030 C000300 0.00
031 A000300 1
031 B000300 0
032 000300 0
033 000300 15
<PAGE> PAGE 14
034 000300 Y
035 000300 36
036 A000300 N
036 B000300 0
042 A000300 0
042 B000300 0
042 C000300 100
042 D000300 0
042 E000300 0
042 F000300 0
042 G000300 0
042 H000300 0
043 000300 128
044 000300 0
045 000300 Y
046 000300 N
047 000300 Y
048 000300 0.000
048 A010300 250000
048 A020300 0.400
048 B010300 150000
048 B020300 0.375
048 C010300 150000
048 C020300 0.350
048 D010300 0
048 D020300 0.000
048 E010300 0
048 E020300 0.000
048 F010300 0
048 F020300 0.000
048 G010300 0
048 G020300 0.000
048 H010300 0
048 H020300 0.000
048 I010300 0
048 I020300 0.000
048 J010300 0
048 J020300 0.000
048 K010300 550000
048 K020300 0.325
055 A000300 Y
055 B000300 N
056 000300 Y
057 000300 N
062 A000300 Y
062 B000300 0.0
062 C000300 0.0
062 D000300 0.0
062 E000300 23.4
062 F000300 0.0
062 G000300 0.0
<PAGE> PAGE 15
062 H000300 0.0
062 I000300 0.0
062 J000300 0.0
062 K000300 0.0
062 L000300 0.0
062 M000300 0.0
062 N000300 0.0
062 O000300 76.1
062 P000300 0.0
062 Q000300 0.0
062 R000300 0.0
063 A000300 0
063 B000300 1.8
064 A000300 Y
064 B000300 N
070 A010300 Y
070 A020300 N
070 B010300 N
070 B020300 N
070 C010300 N
070 C020300 N
070 D010300 N
070 D020300 N
070 E010300 Y
070 E020300 N
070 F010300 N
070 F020300 N
070 G010300 Y
070 G020300 N
070 H010300 N
070 H020300 N
070 I010300 Y
070 I020300 N
070 J010300 Y
070 J020300 N
070 K010300 N
070 K020300 N
070 L010300 N
070 L020300 N
070 M010300 N
070 M020300 N
070 N010300 N
070 N020300 N
070 O010300 Y
070 O020300 N
070 P010300 Y
070 P020300 N
070 Q010300 N
070 Q020300 N
070 R010300 N
070 R020300 N
<PAGE> PAGE 16
071 A000300 147628
071 B000300 188346
071 C000300 424816
071 D000300 35
072 A000300 6
072 B000300 10587
072 C000300 0
072 D000300 0
072 E000300 0
072 F000300 820
072 G000300 20
072 H000300 0
072 I000300 79
072 J000300 26
072 K000300 0
072 L000300 16
072 M000300 3
072 N000300 0
072 O000300 0
072 P000300 0
072 Q000300 0
072 R000300 6
072 S000300 10
072 T000300 128
072 U000300 0
072 V000300 0
072 W000300 9
072 X000300 1117
072 Y000300 0
072 Z000300 9470
072AA000300 1694
072BB000300 9
072CC010300 523
072CC020300 0
072DD010300 8270
072DD020300 1200
072EE000300 803
073 A010300 0.0000
073 A020300 0.0000
073 B000300 0.0000
073 C000300 0.0000
074 A000300 43
074 B000300 0
074 C000300 109389
074 D000300 356234
074 E000300 0
074 F000300 0
074 G000300 0
074 H000300 0
074 I000300 0
074 J000300 0
<PAGE> PAGE 17
074 K000300 0
074 L000300 6453
074 M000300 45
074 N000300 472164
074 O000300 0
074 P000300 154
074 Q000300 0
074 R010300 0
074 R020300 0
074 R030300 0
074 R040300 4246
074 S000300 0
074 T000300 467764
074 U010300 40721
074 U020300 6346
074 V010300 0.00
074 V020300 0.00
074 W000300 0.0000
074 X000300 7437
074 Y000300 0
075 A000300 0
075 B000300 487574
076 000300 0.00
SIGNATURE GERALD M. RICHARD
TITLE TREASURER
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 021
<NAME> INSURED PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 2134880243
<INVESTMENTS-AT-VALUE> 2268907675
<RECEIVABLES> 69408393
<ASSETS-OTHER> 225817
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2338541885
<PAYABLE-FOR-SECURITIES> 39512923
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 15640539
<TOTAL-LIABILITIES> 55153462
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2171532899
<SHARES-COMMON-STOCK> 189947796
<SHARES-COMMON-PRIOR> 198801419
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (22171908)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 134027432
<NET-ASSETS> 1533085839
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 70946928
<OTHER-INCOME> 0
<EXPENSES-NET> (8000591)
<NET-INVESTMENT-INCOME> 62946337
<REALIZED-GAINS-CURRENT> 19810583
<APPREC-INCREASE-CURRENT> 26889548
<NET-CHANGE-FROM-OPS> 109646468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (43966193)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 2457335
<NUMBER-OF-SHARES-REDEEMED> (13751828)
<SHARES-REINVESTED> 2440870
<NET-CHANGE-IN-ASSETS> (83244497)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (41982490)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 4257876
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8000591
<AVERAGE-NET-ASSETS> 1557843046
<PER-SHARE-NAV-BEGIN> 7.91
<PER-SHARE-NII> .23
<PER-SHARE-GAIN-APPREC> .16
<PER-SHARE-DIVIDEND> (.23)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.07
<EXPENSE-RATIO> .43
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 022
<NAME> INSURED PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 2134880243
<INVESTMENTS-AT-VALUE> 2268907675
<RECEIVABLES> 69408393
<ASSETS-OTHER> 225817
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2338541885
<PAYABLE-FOR-SECURITIES> 39512923
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 15640539
<TOTAL-LIABILITIES> 55153462
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2171532899
<SHARES-COMMON-STOCK> 84348645
<SHARES-COMMON-PRIOR> 91463092
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (22171908)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 134027432
<NET-ASSETS> 680291230
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 70946928
<OTHER-INCOME> 0
<EXPENSES-NET> (8000591)
<NET-INVESTMENT-INCOME> 62946337
<REALIZED-GAINS-CURRENT> 19810583
<APPREC-INCREASE-CURRENT> 26889548
<NET-CHANGE-FROM-OPS> 109646468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (17219221)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3173222
<NUMBER-OF-SHARES-REDEEMED> (11452914)
<SHARES-REINVESTED> 1165245
<NET-CHANGE-IN-ASSETS> (83244497)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (41982490)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 4257876
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8000591
<AVERAGE-NET-ASSETS> 706492914
<PER-SHARE-NAV-BEGIN> 7.91
<PER-SHARE-NII> .19
<PER-SHARE-GAIN-APPREC> .16
<PER-SHARE-DIVIDEND> (.19)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.07
<EXPENSE-RATIO> 1.19
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 023
<NAME> INSURED PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 2134880243
<INVESTMENTS-AT-VALUE> 2268907675
<RECEIVABLES> 69408393
<ASSETS-OTHER> 225817
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2338541885
<PAYABLE-FOR-SECURITIES> 39512923
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 15640539
<TOTAL-LIABILITIES> 55153462
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2171532899
<SHARES-COMMON-STOCK> 2528566
<SHARES-COMMON-PRIOR> 2394049
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (22171908)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 134027432
<NET-ASSETS> 20403152
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 70946928
<OTHER-INCOME> 0
<EXPENSES-NET> (8000591)
<NET-INVESTMENT-INCOME> 62946337
<REALIZED-GAINS-CURRENT> 19810583
<APPREC-INCREASE-CURRENT> 26889548
<NET-CHANGE-FROM-OPS> 109646468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (480979)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 420142
<NUMBER-OF-SHARES-REDEEMED> (330374)
<SHARES-REINVESTED> 44749
<NET-CHANGE-IN-ASSETS> (83244497)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (41982490)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 4257876
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8000591
<AVERAGE-NET-ASSETS> 19957758
<PER-SHARE-NAV-BEGIN> 7.91
<PER-SHARE-NII> .19
<PER-SHARE-GAIN-APPREC> .16
<PER-SHARE-DIVIDEND> (.19)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.07
<EXPENSE-RATIO> 1.25
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 024
<NAME> INSURED PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 2134880243
<INVESTMENTS-AT-VALUE> 2268907675
<RECEIVABLES> 69408393
<ASSETS-OTHER> 225817
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2338541885
<PAYABLE-FOR-SECURITIES> 39512923
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 15640539
<TOTAL-LIABILITIES> 55153462
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2171532899
<SHARES-COMMON-STOCK> 6145439
<SHARES-COMMON-PRIOR> 6544245
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (22171908)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 134027432
<NET-ASSETS> 49608202
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 70946928
<OTHER-INCOME> 0
<EXPENSES-NET> (8000591)
<NET-INVESTMENT-INCOME> 62946337
<REALIZED-GAINS-CURRENT> 19810583
<APPREC-INCREASE-CURRENT> 26889548
<NET-CHANGE-FROM-OPS> 109646468
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1279944)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 5218856
<NUMBER-OF-SHARES-REDEEMED> (5697499)
<SHARES-REINVESTED> 79837
<NET-CHANGE-IN-ASSETS> (83244497)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (41982490)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 4257876
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 8000591
<AVERAGE-NET-ASSETS> 47482602
<PER-SHARE-NAV-BEGIN> 7.91
<PER-SHARE-NII> .22
<PER-SHARE-GAIN-APPREC> .16
<PER-SHARE-DIVIDEND> (.22)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 8.07
<EXPENSE-RATIO> .68
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 031
<NAME> LIMITED MATURITY PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 463802746
<INVESTMENTS-AT-VALUE> 465622490
<RECEIVABLES> 6453261
<ASSETS-OTHER> 88035
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 472163786
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4399523
<TOTAL-LIABILITIES> 4399523
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 470694470
<SHARES-COMMON-STOCK> 39113326
<SHARES-COMMON-PRIOR> 42089848
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (4749951)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1819744
<NET-ASSETS> 388697701
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 10587310
<OTHER-INCOME> 0
<EXPENSES-NET> (1116996)
<NET-INVESTMENT-INCOME> 9470314
<REALIZED-GAINS-CURRENT> 1684697
<APPREC-INCREASE-CURRENT> 523240
<NET-CHANGE-FROM-OPS> 11678251
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (7951247)
<DISTRIBUTIONS-OF-GAINS> (665999)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1313166
<NUMBER-OF-SHARES-REDEEMED> (4812927)
<SHARES-REINVESTED> 523239
<NET-CHANGE-IN-ASSETS> (36387351)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (5632124)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 820561
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1116996
<AVERAGE-NET-ASSETS> 403800388
<PER-SHARE-NAV-BEGIN> 9.91
<PER-SHARE-NII> .20
<PER-SHARE-GAIN-APPREC> .05
<PER-SHARE-DIVIDEND> (.20)
<PER-SHARE-DISTRIBUTIONS> (.02)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 9.94
<EXPENSE-RATIO> .40
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 032
<NAME> LIMITED MATURITY PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 463802746
<INVESTMENTS-AT-VALUE> 465622490
<RECEIVABLES> 6453261
<ASSETS-OTHER> 88035
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 472163786
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4399523
<TOTAL-LIABILITIES> 4399523
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 470694470
<SHARES-COMMON-STOCK> 6323238
<SHARES-COMMON-PRIOR> 7170644
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (4749951)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1819744
<NET-ASSETS> 62853560
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 10587310
<OTHER-INCOME> 0
<EXPENSES-NET> (1116996)
<NET-INVESTMENT-INCOME> 9470314
<REALIZED-GAINS-CURRENT> 1684697
<APPREC-INCREASE-CURRENT> 523240
<NET-CHANGE-FROM-OPS> 11678251
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1197025)
<DISTRIBUTIONS-OF-GAINS> (108062)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 646930
<NUMBER-OF-SHARES-REDEEMED> (1582402)
<SHARES-REINVESTED> 88066
<NET-CHANGE-IN-ASSETS> (36387351)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (5632124)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 820561
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1116996
<AVERAGE-NET-ASSETS> 66975724
<PER-SHARE-NAV-BEGIN> 9.91
<PER-SHARE-NII> .18
<PER-SHARE-GAIN-APPREC> .05
<PER-SHARE-DIVIDEND> (.18)
<PER-SHARE-DISTRIBUTIONS> (.02)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 9.94
<EXPENSE-RATIO> .76
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 033
<NAME> LIMITED MATURITY PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 463802746
<INVESTMENTS-AT-VALUE> 465622490
<RECEIVABLES> 6453261
<ASSETS-OTHER> 88035
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 472163786
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4399523
<TOTAL-LIABILITIES> 4399523
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 470694470
<SHARES-COMMON-STOCK> 22634
<SHARES-COMMON-PRIOR> 9519
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (4749951)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1819744
<NET-ASSETS> 224294
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 10587310
<OTHER-INCOME> 0
<EXPENSES-NET> (1116996)
<NET-INVESTMENT-INCOME> 9470314
<REALIZED-GAINS-CURRENT> 1684697
<APPREC-INCREASE-CURRENT> 523240
<NET-CHANGE-FROM-OPS> 11678251
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (2815)
<DISTRIBUTIONS-OF-GAINS> (293)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 17368
<NUMBER-OF-SHARES-REDEEMED> (4550)
<SHARES-REINVESTED> 297
<NET-CHANGE-IN-ASSETS> (36387351)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (5632124)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 820561
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1116996
<AVERAGE-NET-ASSETS> 158034
<PER-SHARE-NAV-BEGIN> 9.88
<PER-SHARE-NII> .18
<PER-SHARE-GAIN-APPREC> .05
<PER-SHARE-DIVIDEND> (.18)
<PER-SHARE-DISTRIBUTIONS> (.02)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 9.91
<EXPENSE-RATIO> .77
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 034
<NAME> LIMITED MATURITY PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 463802746
<INVESTMENTS-AT-VALUE> 465622490
<RECEIVABLES> 6453261
<ASSETS-OTHER> 88035
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 472163786
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 4399523
<TOTAL-LIABILITIES> 4399523
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 470694470
<SHARES-COMMON-STOCK> 1607813
<SHARES-COMMON-PRIOR> 1602198
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (4749951)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 1819744
<NET-ASSETS> 15988708
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 10587310
<OTHER-INCOME> 0
<EXPENSES-NET> (1116996)
<NET-INVESTMENT-INCOME> 9470314
<REALIZED-GAINS-CURRENT> 1684697
<APPREC-INCREASE-CURRENT> 523240
<NET-CHANGE-FROM-OPS> 11678251
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (319227)
<DISTRIBUTIONS-OF-GAINS> (28170)
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1565899
<NUMBER-OF-SHARES-REDEEMED> 1581410)
<SHARES-REINVESTED> 21126
<NET-CHANGE-IN-ASSETS> (36387351)
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (5632124)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 820561
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 1116996
<AVERAGE-NET-ASSETS> 16639694
<PER-SHARE-NAV-BEGIN> 9.91
<PER-SHARE-NII> .19
<PER-SHARE-GAIN-APPREC> .05
<PER-SHARE-DIVIDEND> (.19)
<PER-SHARE-DISTRIBUTIONS> (.02)
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 9.94
<EXPENSE-RATIO> .50
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 011
<NAME> NATIONAL PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 1321899204
<INVESTMENTS-AT-VALUE> 1416686830
<RECEIVABLES> 52433575
<ASSETS-OTHER> 222591
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1469342996
<PAYABLE-FOR-SECURITIES> 14653624
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 9782539
<TOTAL-LIABILITIES> 24436163
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1419039044
<SHARES-COMMON-STOCK> 94625244
<SHARES-COMMON-PRIOR> 97261338
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (67191087)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 93058876
<NET-ASSETS> 977602420
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 46915487
<OTHER-INCOME> 0
<EXPENSES-NET> (5733108)
<NET-INVESTMENT-INCOME> 41182379
<REALIZED-GAINS-CURRENT> 10075551
<APPREC-INCREASE-CURRENT> 20809440
<NET-CHANGE-FROM-OPS> 72067370
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (29113389)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1486925
<NUMBER-OF-SHARES-REDEEMED> (5524737)
<SHARES-REINVESTED> 1401718
<NET-CHANGE-IN-ASSETS> 4841148
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (77266638)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3479545
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5733108
<AVERAGE-NET-ASSETS> 979021857
<PER-SHARE-NAV-BEGIN> 10.11
<PER-SHARE-NII> .30
<PER-SHARE-GAIN-APPREC> .22
<PER-SHARE-DIVIDEND> (.30)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.33
<EXPENSE-RATIO> .56
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 012
<NAME> NATIONAL PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 1321899204
<INVESTMENTS-AT-VALUE> 1416686830
<RECEIVABLES> 52433575
<ASSETS-OTHER> 222591
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1469342996
<PAYABLE-FOR-SECURITIES> 14653624
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 9782539
<TOTAL-LIABILITIES> 24436163
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1419039044
<SHARES-COMMON-STOCK> 38497625
<SHARES-COMMON-PRIOR> 39501944
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (67191087)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 93058876
<NET-ASSETS> 397608975
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 46915487
<OTHER-INCOME> 0
<EXPENSES-NET> (5733108)
<NET-INVESTMENT-INCOME> 41182379
<REALIZED-GAINS-CURRENT> 10075551
<APPREC-INCREASE-CURRENT> 20809440
<NET-CHANGE-FROM-OPS> 72067370
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (10343570)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3021648
<NUMBER-OF-SHARES-REDEEMED> (4515780)
<SHARES-REINVESTED> 489813
<NET-CHANGE-IN-ASSETS> 4841148
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (77266638)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3479545
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5733108
<AVERAGE-NET-ASSETS> 399557582
<PER-SHARE-NAV-BEGIN> 10.11
<PER-SHARE-NII> .26
<PER-SHARE-GAIN-APPREC> .22
<PER-SHARE-DIVIDEND> (.26)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.33
<EXPENSE-RATIO> 1.32
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 013
<NAME> NATIONAL PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 1321899204
<INVESTMENTS-AT-VALUE> 1416686830
<RECEIVABLES> 52433575
<ASSETS-OTHER> 222591
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1469342996
<PAYABLE-FOR-SECURITIES> 14653624
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 9782539
<TOTAL-LIABILITIES> 24436163
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1419039044
<SHARES-COMMON-STOCK> 1828287
<SHARES-COMMON-PRIOR> 1314145
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (67191087)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 93058876
<NET-ASSETS> 18891781
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 46915487
<OTHER-INCOME> 0
<EXPENSES-NET> (5733108)
<NET-INVESTMENT-INCOME> 41182379
<REALIZED-GAINS-CURRENT> 10075551
<APPREC-INCREASE-CURRENT> 20809440
<NET-CHANGE-FROM-OPS> 72067370
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (409391)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 612530
<NUMBER-OF-SHARES-REDEEMED> (121550)
<SHARES-REINVESTED> 23162
<NET-CHANGE-IN-ASSETS> 4841148
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (77266638)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3479545
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5733108
<AVERAGE-NET-ASSETS> 15986823
<PER-SHARE-NAV-BEGIN> 10.11
<PER-SHARE-NII> .26
<PER-SHARE-GAIN-APPREC> .22
<PER-SHARE-DIVIDEND> (.26)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.33
<EXPENSE-RATIO> 1.37
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.
<SERIES>
<NUMBER> 014
<NAME> NATIONAL PORTFOLIO
<S> <C>
<PERIOD-TYPE> 6-MOS
<FISCAL-YEAR-END> JUN-30-1997
<PERIOD-START> JUL-01-1996
<PERIOD-END> DEC-31-1996
<INVESTMENTS-AT-COST> 1321899204
<INVESTMENTS-AT-VALUE> 1416686830
<RECEIVABLES> 52433575
<ASSETS-OTHER> 222591
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 1469342996
<PAYABLE-FOR-SECURITIES> 14653624
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 9782539
<TOTAL-LIABILITIES> 24436163
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 1419039044
<SHARES-COMMON-STOCK> 4914592
<SHARES-COMMON-PRIOR> 4337089
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (67191087)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 93058876
<NET-ASSETS> 50803657
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 46915487
<OTHER-INCOME> 0
<EXPENSES-NET> (5733108)
<NET-INVESTMENT-INCOME> 41182379
<REALIZED-GAINS-CURRENT> 10075551
<APPREC-INCREASE-CURRENT> 20809440
<NET-CHANGE-FROM-OPS> 72067370
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (1316029)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 3872733
<NUMBER-OF-SHARES-REDEEMED> (3349174)
<SHARES-REINVESTED> 53944
<NET-CHANGE-IN-ASSETS> 4841148
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> (77266638)
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3479545
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 5733108
<AVERAGE-NET-ASSETS> 46256717
<PER-SHARE-NAV-BEGIN> 10.12
<PER-SHARE-NII> .29
<PER-SHARE-GAIN-APPREC> .22
<PER-SHARE-DIVIDEND> (.29)
<PER-SHARE-DISTRIBUTIONS> 0
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 10.34
<EXPENSE-RATIO> .81
<AVG-DEBT-OUTSTANDING> 0
<AVG-DEBT-PER-SHARE> 0
</TABLE>
