WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000775370
<NAME> SMITH BARNEY MUNI FUNDS, INC.
<SERIES>
<NUMBER> 1
<NAME> NATIONAL PORTFOLIO - CLASS B
<S> <C>
<PERIOD-TYPE> 12-MOS
<FISCAL-YEAR-END> MAR-31-2000
<PERIOD-END> MAR-31-2000
<INVESTMENTS-AT-COST> 420,876,216
<INVESTMENTS-AT-VALUE> 425,813,075
<RECEIVABLES> 9,537,788
<ASSETS-OTHER> 78,616
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 435,429,479
<PAYABLE-FOR-SECURITIES> 8,093,152
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 1,218,585
<TOTAL-LIABILITIES> 9,311,737
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 430,312,125
<SHARES-COMMON-STOCK> 3,315,272
<SHARES-COMMON-PRIOR> 2,611,236
<ACCUMULATED-NII-CURRENT> 289,999
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> (9,421,241)
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 4,936,859
<NET-ASSETS> 426,117,742
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 27,660,634
<OTHER-INCOME> 0
<EXPENSES-NET> 3,319,923
<NET-INVESTMENT-INCOME> 24,340,711
<REALIZED-GAINS-CURRENT> (9,278,871)
<APPREC-INCREASE-CURRENT> (25,555,727)
<NET-CHANGE-FROM-OPS> (10,493,887)
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> 1,998,790
<DISTRIBUTIONS-OF-GAINS> 21,857
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 1,886,113
<NUMBER-OF-SHARES-REDEEMED> 1,264,157
<SHARES-REINVESTED> 82,080
<NET-CHANGE-IN-ASSETS> (33,359,280)
<ACCUMULATED-NII-PRIOR> (6,771)
<ACCUMULATED-GAINS-PRIOR> 100,490
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 1,990,024
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 3,319,923
<AVERAGE-NET-ASSETS> 39,471,053
<PER-SHARE-NAV-BEGIN> 13.96
<PER-SHARE-NII> 0.67
<PER-SHARE-GAIN-APPREC> (1.03)
<PER-SHARE-DIVIDEND> 0.66
<PER-SHARE-DISTRIBUTIONS> 0.01
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 12.93
<EXPENSE-RATIO> 1.18
</TABLE>