The Prince George's County school desegregation trial ended today, exactly eight weeks after it began, with a U.S. district court judge saying that officials have run the schools as best they can.

U.S. District Judge Frank A. Kaufman stopped short of saying what his final decision will be--whether he would order any busing changes in county schools that may violate any guidelines or standards for racial balance the court might impose.

But he remarked: "It seems to me that those who have been running the school system have been running it in good faith."

The judge also said that the schools had met the "constitutional standards" for desegregation in 1975, the year the court ended its control over the schools.

Kaufman's statement was a blow to the county NAACP, which contends that the school system had never achieved desegregation despite Kaufman's 1972 order to do so, because, among other things, it failed to keep up with the demographic changes in the county during the 1970's.

"It seems to me they tried to do the best they could do," Kaufman said. The current trial is a re-opening of a 1972 desegregation suit filed by the Prince George's branch of the NAACP.

Kaufman, who did most of the talking during the final arguments, said repeatedly that he was impressed by the testimony of school superintendent Edward J. Feeney and other school officials that a good-faith effort was made to run schools on a desegregated basis. At the same time, he said that the court should establish guidelines that would require the school system to take positive action to maintain desegregation.

"I don't think the emphasis on desegregation was always there and I think it could have been," Kaufman said, referring to school closings and other actions affecting racial balance in the schools. "Since we can't re-write history, we can try to do today what should have been done in the past and do it for the future," he said.

The case ran at least two weeks longer than lawyers from either side expected because of Kaufman's detailed approach and lengthy questioning of witnesses during the testimony. Kaufman complimented the lawyers on their conduct, but warned that his decision could take some time.

"I think there are a lot of close issues in this case," he said. "The findings may take me a while."

School officials appeared visibly relieved for the first time during the trial, though school spokesman Brian J. Porter played down the significance of the judge's words. "We have been on the defensive for so long, it was a little numbing walking out of the courtroom today," Porter said. "I don't think that we're in a position to assess the feeling of the court. We can say that the big smoking gun in this case was never produced. Beyond that, it's a question of wait and see," Porter added.