The increase in unit cost of BOS in the year 2009 is significant evidence of government commitment in carrying out the mandate of the Constitution regarding the 20% budget for education. The commitment of this government must also be followed by increased government commitment and community participation in monitoring programs and funding. Based on this, the in-depth knowledge of Microsoft Office is required by the school principal and the school treasurer. It is necessary to an understanding of Microsoft Office that includes: Ms Excel. The aim is for school principals and treasurers to process data based computer applications in accounting / finance, especially financial management BOS to BOS with the orderly administration implemented, transparent, accountable, efficient, timely, and avoid deviations. Keyword :Accounting, BOS