Seven out of 10 parents believe that Fairfax County schools are not teaching their children enough about sex and favor drastic revisions in the county's conservative approach to the topic, according to a just-concluded survey.

Despite the overwhelming results of the poll, members of the county school board said yesterday they don't plan any immediate changes in the program, considered to be one of the most restricted in the Washington area.

"Personnaly, I hope we just leave it alone," said board member Anthony Lane, recalling the ruckus the school system encountered three years ago when it devised the current program. "The last time around it was a really unpleasant experience; you just can't please everybody."

Educators said the current program, which prohibits teachers from answering many students' questions about sex, proved to be as highly unpopular with adults as the sex course has been with students. In a mail survey answered by 1,014 paretns, only 1 in 4 approved the current sex education curriculum.

Only 2 percent of Fairfax's 60,000 high school students are enrolled in the sex education course, and critics blame the lack of interest on the limited content of the course.

"The kids say the program is Mickey Mouse," says Diane Fary, a sex education instructor at Edison High School. "I hate to say it, but my nine-year old niece already knows the things we're supposed to teach in the course."

School administrators who designed the survey said they are pleased with the survey's response rate and expressed confidence that the results will provide the basis for revising the current sex education curriculum.

School board members interviewed yesterday said, however, they are confronted by problems that require more immediate attention than revisions to the sex courses. "I doubt we will make any major changes this year in the program," said board member Robert Frye, who said the board first must deal with budget questions and school-closing issues.

The county began reviewing its current sex education program last summer after the Virginia State Board of Education adopted guidelines far more liberal than those in the Northern Virginia system, generally regarded as one of the most progressive school systems in the state.

The Fairfax program, adopted in 1976, prohibits teachers from discussing abortion, birth control, homosexuality, masturbation or incest. It was adopted after conservative groups pressed the board for a very limited program.

This year some of the same groups, joined by the Arlington Diocese of the Catholic Church, have been lobbying for retaining the current program, arguing that the home -- not the public schoolroom -- is the proper place for sex education.

The mail survey, answered by 1,014 parents, and a similar one answered by 250 high school students, however, indicated sharp disagreement with the current limits on sex education.

Ninety-seven percent of the parents responding to the mail survey said they favored some form of sex education in the schools. The survey also found strong support for allowing teachers to discuss the topics that the current program bans.

Almost 8 out of 10 parents favored separate classes for boys and girls, but less than half of the students surveyed agreed. Such classes are now separate.