CENTENNIAL GOVERNMENT TRUST
                 Supplement dated June 15, 1998 to the
       Statement of Additional Information dated October 1, 1997

This  Supplement  to  the  Statement  of  Additional  Information  replaces  the
Supplement  dated  December  1, 1997 and  changes the  Statement  of  Additional
Information as follows:

1. The sixth sentence under the section entitled "Trustees and Officers" on page
A-1 is modified as follows:

      All of the officers except Mr. Carbuto, Ms. Wolf and Mr. Zimmer hold
      similar positions with each of the Denver Oppenheimer funds.

2. The biography for Dorothy  Warmack under the section  entitled  "Trustees and
Officers" on page A-3 is deleted.

3. Delete the fifth  paragraph in the section  entitled  "Investment  Management
Services" on pages A-7 and replace it with the following:

      Independently  of  the  Money  Market  Trust's   Agreement,   the  Manager
voluntarily agreed to waive a portion of the management fee otherwise payable to
it by the Money  Market  Trust  during the period from  December 1, 1991 through
November 21, 1997.  For fiscal year ended June 30, 1995,  June 30, 1996 and June
30, 1997,  the  reimbursements  by the Manager to Money Market Trust were $0, $0
and  $4,890,123,  respectively.  Contemporaneously  with the  amendment of Money
Market Trust's  Agreement with the Manager,  the Manager  withdrew its voluntary
waiver on November 21, 1997.

4. The list of Corporate  Industry  Classifications  (Exhibit B) on page A-43 is
modified by including the following new classification: Asset Backed.


June 15, 1998                                                 PX0170.002