<ARTICLE> 6
<CIK> 0000225635
<NAME> MERRILL LYNCH MUNICIPAL BOND FUND, INC.

   <NUMBER> 024
   <NAME> INSURED PORTFOLIO

                             
<PERIOD-TYPE>                   12-MOS
<FISCAL-YEAR-END>                          JUN-30-2000
<PERIOD-START>                             JUL-01-1999
<PERIOD-END>                               JUN-30-2000
<INVESTMENTS-AT-COST>                       1312721966
<INVESTMENTS-AT-VALUE>                      1350970423
<RECEIVABLES>                                 22478214
<ASSETS-OTHER>                                  796586
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                              1374245223
<PAYABLE-FOR-SECURITIES>                       8128234
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                      5360593
<TOTAL-LIABILITIES>                           13488827
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                    1401317344
<SHARES-COMMON-STOCK>                         13492271
<SHARES-COMMON-PRIOR>                         10433764
<ACCUMULATED-NII-CURRENT>                            0
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                     (56788346)
<OVERDISTRIBUTION-GAINS>                    (22021059)
<ACCUM-APPREC-OR-DEPREC>                      38248457
<NET-ASSETS>                                  99325839
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                             87267065
<OTHER-INCOME>                                       0
<EXPENSES-NET>                               (9423415)
<NET-INVESTMENT-INCOME>                       77843650
<REALIZED-GAINS-CURRENT>                    (78541901)
<APPREC-INCREASE-CURRENT>                      7805843
<NET-CHANGE-FROM-OPS>                          7107592
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                    (4738013)
<DISTRIBUTIONS-OF-GAINS>                     (1326468)
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                       11609316
<NUMBER-OF-SHARES-REDEEMED>                  (8952192)
<SHARES-REINVESTED>                             401383
<NET-CHANGE-IN-ASSETS>                     (367812315)
<ACCUMULATED-NII-PRIOR>                              0
<ACCUMULATED-GAINS-PRIOR>                     21753555
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                          5507883
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                9423415
<AVERAGE-NET-ASSETS>                          92228679
<PER-SHARE-NAV-BEGIN>                             7.79
<PER-SHARE-NII>                                    .38
<PER-SHARE-GAIN-APPREC>                          (.32)
<PER-SHARE-DIVIDEND>                             (.38)
<PER-SHARE-DISTRIBUTIONS>                        (.11)
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               7.36
<EXPENSE-RATIO>                                    .68