The Fairfax County Planning Commission this week rejected or put off most proposals submitted to change the county's land-use master plan, in what the commission's chairman called a victory for single-family neighborhoods.

Chairman George M. Lilly said the decisions on the proposed amendments to the county's comprehensive plan reflected a "sentiment against anything with a big impact on single-family areas."

The commission reviewed about 230 proposals to amend the comprehensive plan. A plan amendment is the first of several major steps that a developer must take to advance a project from drawing board to completion, if the land involved lacks the appropriate zoning. Even if a change in the plan is recommended by the planning commission and approved by the County Board of Supervisors, the developer still must attempt to obtain rezoning -- and is by no means guaranteed success.

"This is a long, ongoing process," said one county planning staffer. "The bulldozers aren't going to be out there tomorrow or anytime soon."

Of the amendments considered this week, only 57 were approved and will be sent to the Board of Supervisors for final action this summer. Most proposals approved by the commission either have no great impact on the county or were modified or watered down to allow less intense development, according to planning officials.

About 75 proposals were deferred, some indefinitely and some pending studies or additional citizen comment. Another 65 were withdrawn by developers or denied outright; they will not be forwarded to the county board. About 25 proposed amendments will be heard by the planning commission this summer.

In meetings Wednesday and Thursday night, the commission threw out most of the proposals that would have had the greatest impact on the county. Among them were:

* A controversial bid to build an office park with4.5 million square feet of office space near Reston.

* An expansion of commercial development at Tysons Corner that would have spilled north of the Dulles Access Road into a residential neighborhood by allowing a 98-acre office and town house development there.

* A 20-fold increase in the housing density on an 817-acre tract in the Occoquan watershed in western Fairfax County, where the county won a celebrated court case in January to preserve the rural character of the area.

Although a number of major amendments are still to be considered this summer, Lilly said that "the same pattern" of limiting large-scale commercial proposals "will hold."