[ARTICLE] 6
[CIK] 0000355747
[NAME] SMITH BARNEY INVESTMENT FUNDS, INC.
[SERIES]
   [NUMBER] 1
   [NAME] INVESTMENT GRADE BOND FUND. CLASS B
<TABLE>
<S>                             <C>
[PERIOD-TYPE]                   YEAR
[FISCAL-YEAR-END]                          DEC-31-1998
[PERIOD-END]                               DEC-31-1998
[INVESTMENTS-AT-COST]                      563,558,154
[INVESTMENTS-AT-VALUE]                     613,366,886
[RECEIVABLES]                               14,405,188
[ASSETS-OTHER]                                     409
[OTHER-ITEMS-ASSETS]                                 0
[TOTAL-ASSETS]                             627,772,483
[PAYABLE-FOR-SECURITIES]                             0
[SENIOR-LONG-TERM-DEBT]                              0
[OTHER-ITEMS-LIABILITIES]                      916,294
[TOTAL-LIABILITIES]                            916,294
[SENIOR-EQUITY]                                      0
[PAID-IN-CAPITAL-COMMON]                   578,372,489
[SHARES-COMMON-STOCK]                       19,826,536
[SHARES-COMMON-PRIOR]                       18,898,019
[ACCUMULATED-NII-CURRENT]                        2,060
[OVERDISTRIBUTION-NII]                               0
[ACCUMULATED-NET-GAINS]                      1,322,972
[OVERDISTRIBUTION-GAINS]                             0
[ACCUM-APPREC-OR-DEPREC]                    49,808,732
[NET-ASSETS]                               626,856,189
[DIVIDEND-INCOME]                                    0
[INTEREST-INCOME]                           39,790,644
[OTHER-INCOME]                                       0
[EXPENSES-NET]                               7,136,147
[NET-INVESTMENT-INCOME]                     32,654,497
[REALIZED-GAINS-CURRENT]                    15,949,183
[APPREC-INCREASE-CURRENT]                    3,219,301
[NET-CHANGE-FROM-OPS]                       45,384,379
[EQUALIZATION]                                       0
[DISTRIBUTIONS-OF-INCOME]                   13,742,821
[DISTRIBUTIONS-OF-GAINS]                     7,004,239
[DISTRIBUTIONS-OTHER]                                0
[NUMBER-OF-SHARES-SOLD]                      4,929,844
[NUMBER-OF-SHARES-REDEEMED]                  1,063,022
[SHARES-REINVESTED]                          5,064,349
[NET-CHANGE-IN-ASSETS]                               0
[ACCUMULATED-NII-PRIOR]                              0
[ACCUMULATED-GAINS-PRIOR]                            0
[OVERDISTRIB-NII-PRIOR]                              0
[OVERDIST-NET-GAINS-PRIOR]                           0
[GROSS-ADVISORY-FEES]                        2,618,948
[INTEREST-EXPENSE]                                   0
[GROSS-EXPENSE]                              7,136,147
[AVERAGE-NET-ASSETS]                       251,522,073
[PER-SHARE-NAV-BEGIN]                            13.19
[PER-SHARE-NII]                                  00.70
[PER-SHARE-GAIN-APPREC]                          00.29
[PER-SHARE-DIVIDEND]                             00.72
[PER-SHARE-DISTRIBUTIONS]                        00.37
[RETURNS-OF-CAPITAL]                                 0
[PER-SHARE-NAV-END]                              13.09
[EXPENSE-RATIO]                                  01.53
[AVG-DEBT-OUTSTANDING]                               0
[AVG-DEBT-PER-SHARE]                                 0
</TABLE>