The Capital Centre sports arena in Largo has lost the last vestige of its tax-exempt status and owes Prince George's County more than $500,000 in back taxes, interest and penalties under a ruling yesterday by a state appeals court.

The ruling, which dealt with the tax status of the land the arena occupies, apparently also removes obstacles to the collection of another $2.5 million in taxes, interest and penalties owed on the arena itself, state officials said.

The Court of Special Appeals' ruling resolved a five-year controversy by stating that the land the arena occupies cannot be considered a park.

Capital Centre owner Abe Pollin has failed to pay real estate taxes on either the land or the arena itself since receiving his first tax assessment notice in 1974, according to Richard Bradley, the county's deputy director of finance. Pollin owes a total of more than $3 million in taxes, interest and penalties - about $500,000 of it on the land alone, Bradley said.

Instead of paying, Pollin fought the taxes in two separate legal battles, one over the tax status of the arena and the second over the 60 acres of land the complex occupies under a lease with the Maryland-National Capital Park and Planning Commission.

Pollin's lawyers argued that the land was tax exempt under a special was leased for use as a "park" to provide recreation and entertainment for the public.

Pollin's lawyers, had won every stage of the "pork" battle through administrative tax boards and the state courts, until the Court of Special Appeals rejected their claim yesterday.

In an opinion by Chief Judge Richard Gilbert, the court said the arena and its parking lot "can hardly be said to enhance the purpose of a park, that is, the providing of open natural space; rather, they enhance the commercial interest" of the arena's owners.

Pollin's lawyers still may seek review of the ruling by the state's highest court - the Court of Appeals - but they refused to comment yesterday on their plans.

Last year, that court ruled against Pollin on the tax status of the arena, asserting that the county assessor has the sole power to decide whether taxes are owed on it. Assessor Harry Shipp had ruled that it is taxable.

Despite that May 1978 ruling, the county has not moved to collect the back taxes on the arena, partly because it is difficult to segregate the taxes on the land from the building itself, according to the attorney general's office.

With yesterday's ruling, it is likely the county will go "full speed ahead" to collect the taxes, Assistant Attorney General Peter Taliaferro said.

However, there still may be legal wrangling ahead over the amount of the taxes, interest and penalties due.

About 85 percent of the taxes due would go to the county, according to finance officials. The rest would be collected by the county, but disbursed among the state, the Washington Suburban Sanitary Commission and the park and planning commission.