Educators were attacked for teaching such diverse subjects as birth control and the horror stories of author Stephen King as "far right" groups last year continued to try to censor school curricula, a liberal advocacy group says.

People for the American Way said Wednesday it counted 157 incidents of "extremist pressure on school systems or outright censorship challenges in the 1987-88 school year."The civil liberties group said an "alarming trend is that national and local pressure groups have adopted mainstream tactics. They have lobbied state legislatures on curriculum guidelines and pressured textbook selection committees to reject books and programs that fail to pass their narrow, sectarian litmus test," said Arthur J. Kropp, president of the 270,000-member organization.

Rebecca Hageline, director of communications for one group targeted in the report - Concerned Women for America, said it was typical of People for the American Way's "religious bigotry toward conservative Christians."

"Parents have a right to have input into their children's education," she said.

The report said Concerned Women for America presented the Barlow, Fla., school board with 4,456 petition signatures opposing teaching about contraception in sex education courses. The board agreed the courses should stress abstinence and not mention contraception, the report said.

Among the 157 incidents People for the American Way said it found was a dispute in Panama City, Fla., where a school board said 60 books could not be used on a junior high supplementary reading list without its approval.

The policy later was reversed, but the report said two books, Robert Cormier's "I am the cheese" and Farley Mowat's "Never Cry Wolf," remain banned, and a lawsuit is pending.

People for the American Way said the most frequently challenged authors were Judy Blume and John Steinbeck (in seven cases each), King (four) and Cormier and J.D. Salinger (both three). Steinbeck's novel "Of Mice and Men" was the book most often singled out.

In Parker, Colo., Patricia Hermes' novel "A Solitary Secret" about a 14-year-old girl's experience with incest was moved from the junior high to the high school library after a parent's complaint.

In Crown King, Ariz., a teacher renamed her 666 Reading Club after parents and school board members objected that the number was a biblical sign for the devil. The teacher, who had picked it as the goal for how many pages students should read each month, renamed it the 667 Reading Club.

In Arlington, Texas, in a high school production of "A Chorus Line," a homosexual character was changed to a victim of child abuse and references to sex were deleted.

In Las Cruces, N.M., parents and conservative activists objected to Halloween activities in several elementary schools, as well as Maurice Sendak's "Where the Wild Things Are." The school district modified the activities, but kept the book.

Not all of the so-called censorship incidents came from the conservative end of the political spectrum.

PAW's list of incidents include a ban on in-school meetings of the Teens for Christ Club at the high school in West Fork, Ark., after the American Civil Liberties Union threatened a lawsuit.