Suburban homeowners who appealed their tax assessments in droves this year in the wake of reduced home-selling prices generally are winning only modest reductions in their property taxes or are losing their appeals.

In Montgomery, Prince George's, Fairfax and Arlington counties, most property owners who appealed for tax relief did not get it.

In Montgomery, the 1,531 residential property owners who have so far obtained tax assessment relief will get the largest average property tax cuts in the area, with the amount averaging $157 for this year and growing to a total of $471 in three years. (Maryland phases in increased taxable assessments over three years.) Montgomery County has 280,000 households.

Further, property owners who are seeing home sales prices drop or stabilize in their neighborhoods after years of appreciation will have to wait until the next reassessment to either see that drop reflected in their assessments or use that fact to argue for a reduction.

Devaluation of property prices was often not reflected in this year's assessments, tax officials said, because tax assessments were based on last year's sales prices.

In Prince George's and Montgomery, which levy real estate property taxes under a complex formula applied to Maryland property, residential property owners won $15.7 million and $64.4 million, respectively, in county tax assessment reductions on their homes.

In Prince George's, where 943 residential property values were lowered by assessment officials, the property adjustment translates into reduced tax revenues of $206,751 over three years. This tax decrease averages $73 this year for those who got tax relief, which will grow to $219 in three years. The average reduced assessment totaled $16,711.

Montgomery, as a result of the reduced assessments on the 1,531 properties, will see its tax revenue drop by $721,952 over three years. The average assessment reduction was $42,103.

Arlington, which does not break down its assessments between residential and commercial property, has granted $10.8 million in tax assessment reductions for many kinds of property, out of a total tax base of $18.3 billion. This adjustment will cost the county $82,935 in tax revenue.

Fairfax has reduced the value of its property tax rolls by $150.4 million for all property, including $30.9 million on residential property, for a savings to taxpayers of $1.7 million.

The reductions made so far throughout the Washington area have been approved by staff members in local assessment offices. Property owners unhappy with those decisions have or had the right to appeal to various boards in each jurisdiction. Those boards have begun to hold hearings and render decisions, but the bulk of their work will continue into the fall and winter.

The tax reductions granted are quite small relative to the overall budgets of the counties. Montgomery County's loss of $721,000 amounts only to 0.00048 percent of the county's $1.5 billion budget for fiscal 1991. Prince George's reduction is an even smaller percentage of its nearly $1 billion budget. The tax losses are also very small fractions of the $412 million budget in Arlington County and the $1.4 billion budget in Fairfax.

The supervisors of the tax assessors who granted the reductions noted that they were essentially in the same range as the reductions granted in past years.

The tax assessment notices received by property owners earlier this year reflected sales figures of last year, when housing prices were still following their historical upward trend.

But with the slowdown in the real estate market, some houses are selling below their assessed values, and some aggrieved property owners are arguing they should receive relief because of that.

Assessors rarely if ever grant adjustments on that basis, with the adjustments being granted to reflect inaccurate information on the assessment forms or damage to the property since the last inspection by an assessment officer.

Dena Siri, chief of the real estate division of Fairfax County's Department of Assessments, said the assessments for the property taxes collected in 1991 will be based on movements in this year's market.

Robert Rudnick, Montgomery's supervisor of assessments, said for an orderly assessment process it is crucial that properties be assessed for one period, in his case the market values of properties on Jan. 1.

"My gosh, I can't be making that kind of adjustment on a monthly basis," he said, referring to constant changes in the local real estate market.

But the figures and the tax assessors' rationale are academic to leaders of citizens tax-resistance groups.

"The sales prices of homes {now} are not reflective of the assessments," said Robert R. Denny, a leader of the property tax revolt in Montgomery County.

He said some homeowners in the last year have faced drastically higher property valuations, and after receiving their assessment notices tried to sell their homes in a market where houses often are not worth what they once were. "They are getting hit doubly," he said.

Others may want to stay put in their homes, but will not stand still for the tax bills they are receiving.

Montgomery County's Robert Wooden, who lives on Willard Avenue in Friendship Heights on land bought by his great-grandfather just after the Civil War, saw the tax assessment more than triple on his acre of land and 90-year-old farmhouse. The property was assessed at $231,000 in 1987, but Montgomery County assessed it at $827,000 for 1990. His tax bill grew from $3,200 in 1989 to $3,900 this year.

When he appealed, an assessment officer reduced the assessment by $150,000. Part of Wooden's front yard was legally recorded as a separate lot, and had been assessed as a marketable, buildable lot.

Wooden convinced the assessor that the parcel, measuring only 1,300 square feet, was smaller than the minimum lot size Montgomery County requires for buildable lots for a property and neighborhood of that type. The assessor then decided the property should be valued at an "excess land" rate.

That rate, which had been 50 cents a square foot in his 1987 valuation, Wooden said, was $10 a square foot in 1990.

Wooden now has asked the Montgomery assessment board of appeals to review his entire assessment.