<ARTICLE>                     5
<LEGEND>



                             PS BUSINESS PARKS. INC.
                      EXHIBIT 27 - FINANCIAL DATA SCHEDULE
                           ARTICLE 5 OF REGULATION S-X

</LEGEND>
       <CIK>                                                0000866368
       <NAME>                                  PS Business Parks, Inc.
       <MULTIPLIER>                                                  1
       <CURRENCY>                                               U.S. $

                                                                
       <PERIOD-TYPE>                                             9-MOS
       <FISCAL-YEAR-END>                                   DEC-31-1999
       <PERIOD-START>                                      JAN-01-1999
       <PERIOD-END>                                        SEP-30-1999
       <EXCHANGE-RATE>                                               1
       <CASH>                                              118,988,000
       <SECURITIES>                                                  0
       <RECEIVABLES>                                                 0
       <ALLOWANCES>                                                  0
       <INVENTORY>                                                   0
       <CURRENT-ASSETS>                                    118,988,000
       <PP&E>                                              815,937,000
       <DEPRECIATION>                                     (43,932,000)
       <TOTAL-ASSETS>                                      906,387,000
       <CURRENT-LIABILITIES>                                19,210,000
       <BONDS>                                                       0
       <PREFERRED-MANDATORY>                                         0
       <PREFERRED>                                          55,000,000
       <COMMON>                                                236,000
       <OTHER-SE>                                          497,153,000
       <TOTAL-LIABILITY-AND-EQUITY>                        906,387,000
       <SALES>                                                       0
       <TOTAL-REVENUES>                                     93,780,000
       <CGS>                                                         0
       <TOTAL-COSTS>                                        26,021,000
       <OTHER-EXPENSES>                                     23,980,000
       <LOSS-PROVISION>                                              0
       <INTEREST-EXPENSE>                                    2,658,000
       <INCOME-PRETAX>                                      30,352,000
       <INCOME-TAX>                                                  0
       <INCOME-CONTINUING>                                  30,352,000
       <DISCONTINUED>                                                0
       <EXTRAORDINARY>                                               0
       <CHANGES>                                                     0
       <NET-INCOME>                                         30,352,000
       <EPS-BASIC>                                              1.19
       <EPS-DILUTED>                                              1.19