PRINCE GEORGE'S County's school board has now taken its desegregation plan to the federal court in Baltimore and laid it before Judge Frank A. Kaufman. At this point in a very long lawsuit, the school board is entitled to be allowed to proceed with its own proposal. The board is clearly working in good faith to achieve a greater degree of racial integration in its classrooms. It is going to try to accomplish that necessary purpose in a way that gives children positive incentives to transfer among schools, rather than ordering them to move.

The board has adopted Superintendent John A. Murphy's concept of 10 magnet schools equipped with special programs and strong teaching staffs. It will not be inexpensive, but the county executive, Parris Glendening, has said he believes the money will be available. n the past the board has repeatedly misread the law, mistaken its requirements and wasted time and money on legal appeals that it has uniformly lost. Its reliance on a defective legal strategy seems to have ended. Instead the board has turned to its educational resources -- which are substantial -- to build magnet schools powerful enough to draw children into new patterns that will meet constitutional standards while simultaneously giving individual children advantages they did not previously enjoy.

It's not certain that the magnet schools will work. Probably there will be great successes in some schools and failures elsewhere. But if failures develop, the school system and, if necessary, the judge can deal with them case by case.

To spend money on magnet schools is preferable by any measure to the county-wide busing order that an advisory committee has suggested to Judge Kaufman. That kind of remedy would always remain available, should all else fail. But it ought to be regarded as the last resort -- and it's highly unlikely to be needed.

The NAACP and its lawyers have done a public service by raising the question of racial proportions in the Prince George's schools and pursuing it through 13 weary years of litigation. It's fair to say that the county school system, like many others, would not have been likely to move forcefully toward desegregation without being pushed by the federal courts. But it is also evident that attitudes have changed in Prince George's.

The school board is now wholeheartedly and vigorously supporting a plan designed not only to remedy attendance patterns but to remedy them in ways that have some real hope of remaining stable over the years. That's more than a court's busing order can do. The school board has earned the right to proceed with a plan that promises to expand educational opportunities for every child in the county.