A study by Prince George's County school officials has concluded that if all elementary school students in the county attended their neighborhood schools instead of riding buses to distant ones the number of one-race schools would increase dramatically.

The study, released last night, was commissioned by a school board advisory commitee set up in an effort to reduce busing in the county. It shows that 34 elementary schools would have enrollments 90 percent or more of one race. This year, only three elementary schools have such a high single-race composition.

The study also shows that 74 schools would have enrollments between 10 percent to 50 percent black, six more schools than this year. The 10-percent to 50-percent range was considered optimum for racial integration by the federal court that ordered Prince George's County to desegregate its schools in 1972.

The advisory committee decided last night to examine the staff analysis and consider possible ways to obtain neighborhood schools with racial compositions no greater than 80 percent one race. Any decision to seek attendance boundary changes to accomplish such a goal would require more staff studies and, ultimately, would be up to the county school board.

No figures were given last night on the number of elementary school students who, if attending neighborhood schools, would no longer have to ride a school bus every day.

Since November the advisory committee has been looking into ways to alter busing assignments set by the federal court eight years ago to desegregate the county's public schools.

Those busing patterns have never been changed despite dramatic changes in the county's racial composition that have occurred as black families moved into previously white neighborhoods.

The black student population has jumped from 28 percent of the system's students in 1972 to nearly 50 percent this year. As a result, where busing patterns were designed to desegregate schools, eight years later many of those schools have begun to resegregate.

The study released last night, school officials emphasized, was simply a statistical analysis rather than a set of recommendations. At the request of the advisory committee, the staff reworked attendance zones to see how racial balanace in elementary schools would be affected by allowing students to attend the schools closet to their homes, school officials said.

"It is a study and an analysis, and it is no more than a study and an a analysis," said Edward M. Felegy, assistant superintendent.

The schools whose racial composition would be most dramatically affected if busing were halted are in the predominantly black areas inside the Capital Beltway and in the predominantly white Laurel and Bowie areas.

Of the 34 schools that would have student populations more than 90 percent one race, 19 would be predominantly black. Beaver Heights Elementary School in Capital Heights, John Carroll in Landover, Matthew Henson, also in Landover, and Owens Road in Oxon Hill would be 98 percent or more black. Bond Mill Elementary School in Laurel, Chapel Forge Elementary School in Bowie, Greenbelt North End Elementary School and Yorktown Elementary School in Bowie would be under 2 percent black.