Owners of a parking lot concession at National Airport, who for four years have refused to pay taxes to Arlington County, have filed suit claiming the county has no right to levy a business tax on merchants operating on land ceded to the federal government by the state.

The suit, filed this week in Arlington's Circuit Court, challenges the agreement between the federal government, the state and the county that delineates the intricate web of authority governing the airport property.

Lawyers for Parkington Inc., a D.C. parking lot company owing more than $7,000 in back taxes to the county, say Arlington never was given specific authority to tax businesses by demanding a license fee.

"Yes, everybody must pay taxes," said Parkington attorney Laurence G. Roman yesterday. "But here we have a situation where certain rights have been given to the federal government and the state has given up some of its rights. It's technical. The question is: Isn't the county doing something that's an improper imposition of a tax?"

"I don't know why he's making that claim," said Geraldine Whiting, Arlington's commissioner of revenue, a defendant in the suit. "The issue has already been decided."

Potentially, the suit could affect about 40 businesses operating at National through leases with the federal government. Many now pay sales and use taxes to the state as well as license fees to the county. County officials are confident the challenge will be turned back in the courts.

"I don't think we'll have any problem with it," said County Board member Walter Frankland, who, along with the board's four other members, is named in the suit. "We've been through this before."

Ever since Virginia gave the land to the federal government in 1940, the National Airport property has been involved in jurisdictional disputes. And over the years, hackles have been raised among local legislators who felt suburban taxpayers were not getting their fair share of tax benefits from the airport.

Although Congress gave other jurisdictions around the country taxation rights over federal reserves through the so-called Buck Act of 1940, National remained a nettlesome exception.

"This is all kind of fun," said assistant county attorney David Lasso, who has defended the county in similar challenges before. "It's federal property. hBut, territorially, it's still in Virginia and it's still in Arlington."

Lasso said the issue of business license taxes, which many businessmen consider unfair in any case because they are levied against gross receipts, was decided in 1970 when Congress passed the Airports and Airways Development Act. Introduced by former 10th District Congressman Joel T. Broyhill, it finally applied taxing provisions of the Buck Act to National Airport.

"I think it's relatively clear," said Lasso. "We'll just let the court resolve it."