The Prince George's County schools now face a choice. The federal Court of Appeals said last week that they are going to have to go further in desegregating the system. The choice isn't whether to proceed, but how.

One possibility is to follow the Green committee's plan. Federal Judge Frank A. Kaufman, who has been handling this case since it was first brought in 1972, appointed a committee headed by Robert L. Green, the president of the University of the District of Columbia, to advise him on ways to complete the desegregation of these schools. Last month the committee recommended extensive reasthe county. It would involve pairing of schools, closing some schools and reopening others. There is an alternative, andit's far more promising.

The county's school superintendent, John A. Murphy, proposes magnet schools. One suggestion is extra services at schools where they would advance desegregation. For example, Mr. Murphy says, some schools might provide care before and after normal school hours for the children of working parents. And how about unusual educational opportunities? Two of the county's high schools, Eleanor Roosevelt and Oxon Hill, already have advanced science programs. Others, including elementary schools, might offer intensive instruction in foreign languages or music. Mr. Murphy would rather spend money on computers, music labs and teaching than on reopening schools that were in poor condition when they closed.

Prince George's County is, geographically, a huge school district. The kind of reassignment and busing that works well in, say, Alexandria is much more difficult in Prince George's because of its size. Its changing demography also has to be taken into account. When this litigationbegan 13 years ago, 24 percent of the county's public school children were black. Currently, 58 percent are black. That change represents mainly the normal and natural movement of black families from the District of Columbia eastward, following the pattern of white families a generation earlier and, like them, seeking good schools as well as suburban houses. To reach the kind of balance that the Green committee envisions would require moving quite a few children over long distances. A magnet program would also mean long commutes. But it would have the important advantage of providing specific benefits to every family that takes part, in addition to advancing the broader public value of desegregation.

Next, the school board must decide whether to appeal the court's decision. Another appeal is a bad idea. The board has lost every round in the 13 years of litigation. The board needs to reconsider its legal tactics and ask itself whether they are accomplishing anything but wasting time and running up its legal costs.