<ARTICLE> 6
<CIK> 0000276776
<NAME> PIONEER BOND FUND

   <NUMBER> 002
   <NAME> PIONEER BOND FUND CLASS B
<CURRENCY> US

                             
<PERIOD-TYPE>                   YEAR
<FISCAL-YEAR-END>                          JUN-30-2000
<PERIOD-END>                               JUN-30-2000
<EXCHANGE-RATE>                                      1
<INVESTMENTS-AT-COST>                        149176608
<INVESTMENTS-AT-VALUE>                       142948704
<RECEIVABLES>                                  3292316
<ASSETS-OTHER>                                     477
<OTHER-ITEMS-ASSETS>                            494315
<TOTAL-ASSETS>                               146735812
<PAYABLE-FOR-SECURITIES>                             0
<SENIOR-LONG-TERM-DEBT>                              0
<OTHER-ITEMS-LIABILITIES>                       854047
<TOTAL-LIABILITIES>                             854047
<SENIOR-EQUITY>                                      0
<PAID-IN-CAPITAL-COMMON>                     162604600
<SHARES-COMMON-STOCK>                          4413872
<SHARES-COMMON-PRIOR>                          5592081
<ACCUMULATED-NII-CURRENT>                        55980
<OVERDISTRIBUTION-NII>                               0
<ACCUMULATED-NET-GAINS>                              0
<OVERDISTRIBUTION-GAINS>                      10550911
<ACCUM-APPREC-OR-DEPREC>                     (6227904)
<NET-ASSETS>                                 145881765
<DIVIDEND-INCOME>                                    0
<INTEREST-INCOME>                             13264833
<OTHER-INCOME>                                       0
<EXPENSES-NET>                                 2419296
<NET-INVESTMENT-INCOME>                       10845537
<REALIZED-GAINS-CURRENT>                     (6904742)
<APPREC-INCREASE-CURRENT>                    (2601649)
<NET-CHANGE-FROM-OPS>                          1339146
<EQUALIZATION>                                       0
<DISTRIBUTIONS-OF-INCOME>                      2547821
<DISTRIBUTIONS-OF-GAINS>                             0
<DISTRIBUTIONS-OTHER>                                0
<NUMBER-OF-SHARES-SOLD>                        1752374
<NUMBER-OF-SHARES-REDEEMED>                    3126491
<SHARES-REINVESTED>                             195908
<NET-CHANGE-IN-ASSETS>                      (43790352)
<ACCUMULATED-NII-PRIOR>                          12118
<ACCUMULATED-GAINS-PRIOR>                            0
<OVERDISTRIB-NII-PRIOR>                              0
<OVERDIST-NET-GAINS-PRIOR>                     3630356
<GROSS-ADVISORY-FEES>                           844331
<INTEREST-EXPENSE>                                   0
<GROSS-EXPENSE>                                2458672
<AVERAGE-NET-ASSETS>                          43288982
<PER-SHARE-NAV-BEGIN>                             8.91
<PER-SHARE-NII>                                   0.50
<PER-SHARE-GAIN-APPREC>                         (0.46)
<PER-SHARE-DIVIDEND>                              0.51
<PER-SHARE-DISTRIBUTIONS>                            0
<RETURNS-OF-CAPITAL>                                 0
<PER-SHARE-NAV-END>                               8.44
<EXPENSE-RATIO>                                   2.05