<TABLE> <S> <C>

<ARTICLE> 6
<CIK> 0000355747
<NAME> GOVERNMENT SECURITIES FUND - CLASS Z
<SERIES>
   <NUMBER> 002
   <NAME> SMITH BARNEY INVESTMENT FUNDS INC.

<S>                             <C>
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          DEC-31-1999
<PERIOD-END>                               DEC-31-1999
<INVESTMENTS-AT-COST>                      657,067,265
<INVESTMENTS-AT-VALUE>                     635,697,343
<RECEIVABLES>                                3,134,058
<ASSETS-OTHER>                                       0
<OTHER-ITEMS-ASSETS>                                 0
<TOTAL-ASSETS>                             638,831,401
<PAYABLE-FOR-SECURITIES>                             0
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                    1,919,127
<TOTAL-LIABILITIES>                          1,919,127
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                   737,142,701
<SHARES-COMMON-STOCK>                        7,010,853
<SHARES-COMMON-PRIOR>                                0
<ACCUMULATED-NII-CURRENT>                      (3,771)
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                   (78,856,734)
<OVERDISTRIBUTION-GAINS>                             0
<ACCUM-APPREC-OR-DEPREC>                    21,369,922
<NET-ASSETS>                               636,912,274
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                           41,711,695
<OTHER-INCOME>                                       0
<EXPENSES-NET>                               5,810,866
<NET-INVESTMENT-INCOME>                     35,900,829
<REALIZED-GAINS-CURRENT>                  (45,975,860)
<APPREC-INCREASE-CURRENT>                 (24,345,994)
<NET-CHANGE-FROM-OPS>                     (34,421,025)
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                    3,940,847
<DISTRIBUTIONS-OF-GAINS>                        32,823
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                      8,528,957
<NUMBER-OF-SHARES-REDEEMED>                  1,941,189
<SHARES-REINVESTED>                            423,085
<NET-CHANGE-IN-ASSETS>                       1,544,253
<ACCUMULATED-NII-PRIOR>                        (2,303)
<ACCUMULATED-GAINS-PRIOR>                 (32,914,781)
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                           0
<GROSS-ADVISORY-FEES>                        3,733,815
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                              5,810,866
<AVERAGE-NET-ASSETS>                        70,244,691
<PER-SHARE-NAV-BEGIN>                             9.97
<PER-SHARE-NII>                                   0.52
<PER-SHARE-GAIN-APPREC>                         (0.97)
<PER-SHARE-DIVIDEND>                              0.53
<PER-SHARE-DISTRIBUTIONS>                         0.00
<RETURNS-OF-CAPITAL>                              0.00
<PER-SHARE-NAV-END>                               8.99
<EXPENSE-RATIO>                                   0.64


</TABLE>