The Fairfax County School Board ended a month of heated debate last night by approving a $395 million budget proposal that places emphasis on reducing class size at the expense of administrative changes proposed by the new school superintendent, Linton Deck.

The controversy surrounding the budget, the first designed by Deck, was in marked contrast to the past. Deck's budget proposal was under fire from the start when he called for a textbook rental fee that would have cost students up to $30 a year Deck scrapped that proposal last week, announcing he had found unanticipated revenue.

The budget approved last night reflects the board's diversion of almost $2 million away from projects, such as increasing the size of the school administration, that were a top priority of Deck.

Part of that sum will be used to reduce class size in the first through fourth grades from 28 pupils for each teacher to a 27-to-1 ratio. This will require hiring more teachers, but the board has not specified how many.

The budget now goes to the County Board of Supervisors, which can -- and usually does -- cut the total but not specific programs. The budget proposal is about 12 percent above current school spending.

Newly appointed School Board member Eltse Carter said the board is sending the community and the school staff a message: "On two items especially . . . we were responsive to the community. We put dollars back into the classroom and signaled a halt to administrative growth iin this [school] district."

Another new board member, Gerald Fill, proposed that the board revamp its budget procedure by establishing its priorities well in advance. The board unanimously approved the suggestion.