Despite intense protests led by black parents and civil leaders in recent weeks, the Montgomery County School Board voted last night to eliminate a requirement that all school employes take a course in black culture.

Although the board's new conservative majority called its approval of the resolution a compromise, the vote prompted about 100 blacks to walk out of the school administration's auditorium in Rockville.

Led by George H. Sealey, head of the county NAACP chapter, they tore up copies of the resolution and deposited the pieces in front of Board President Marian Greenblatt as they walked out. Sealey shouted at Green-blatt: "You are a fraud. You are a fraud."

Following some confusion caused by the sounding of an internal fire alarm bell, about 75 blacks then met in the building's cafeteria where Frank Morris, head of the NAACP's education committee, announced plans to "do monumental political battle" against the board majority. Plans were made for a protest meeting Sunday at Mount Calvary Baptist Church in Rockville.

The board's vote was 4 to 3, with the majority, led by Greenblatt, approving what she called a compromise.

Although the 45-hour black culture course henceforth will be optional for school personnel, all school employes will be required to take a day-and-a-half course in education of minority children each year.

The resolution also requires evaluation of the black culture course by outside experts, with the understanding that the board could reinstate it as a requirement if it is found to be valuable.

The school administration also will develop a series of television presentations on black, Hispanic and Asian cultures for the staff at each school.

Board member Daryl Shaw, a member of the minority, disputed the characteristics of the resolution as a compromise. "A reasonable compromise would be to postpone action," he said.

Before the vote, board member Blair Ewing, another member of the minority, addressed the majority, saying: "Your message in this resolution is that white people know what's best for minorities.It's an insult and an offer to do battle. You are a shame and your motives are entirely political."

Greenblatt then said, "We are concerned primarily about how our children are doing in school, whether they will be able to go on to college and whether they will be able to hold down a job.

"There are many citizens who have taken to slogans and attempted to demean the actions of this board," she said as many black parents booed. "I hope that we realize we share common goals."

Before last night's meeting, Morris of the NAACP, anticipating the out come said the organization intends to inform the public by letters and leaf-lets of the majority's "declaration of war on blacks."

"This is only one battle," Morris said. "We plan to picket their speaking engagements and will be at future meetings in force when the board gets down to budget matters."

He said local NAACP chapters also will set up picket lines at national education meetings next month in New Orleans and Miami that board members plan to attend.

The majority's plan to do away with the mandatory aspect of the black culture course has been vigorously challenged by parents, most of them black. At a hearing on the proposal Tuesday night, only four of 46 speakers supported the move.

About 10 percent of the county's population is black, more than double what it was 10 years ago.

Joseph Barse, Eleanor Zappone and Carol Wallace were elected last November after campaigning on a platform to cut the budget, reduce class size, spend more for textbooks and other supplies and lessen the burden on teachers, including eliminating the mandatory black culture course, which they claim has lowered teacher morale. The three joined board incumbent Greenblatt as a new majority.

The board's minority consists of Elizabeth Spencer, Shaw and Ewing.

A resolution prepared by Spencer was rejected last night by the same 4-to-3 vote that later approved Green-blatt's proposal.

Under Spencer's proposal, the black culture course would have remained a requirement for new teachers and for getting promotions and raises, but not for being recertified as a teacher. Thus, a teacher could have elected to forgo the course if he or she did not want to be eligible for raises or promotions.

The black culture course, made up of 15 three-hour class sessions, was created in 1975 in response to a series of racial incidents at the schools. It was designed to create greater understanding between school employes and black students.

So far, about a tenth of the school system's 12,000 employes have taken the course, which concentrates on the history, psychology and culture of American blacks and costs the county $140,000 a year to teach.

While supporting the mandatory course, the Montgomery County Education Association, bargaining agent for teachers, objects to the requirement that teachers take it outside working hours. Other employes have the option of taking it during working hours.

School Superintendent Charles M. Bernardo has proposed adding $130,000 to next year's budget to hire staff to give the course to teachers during working hours.

Greenblatt has remarked: "That's just taking money away from the classroom, where it's really needed." Greenblatt said the course could cost $5 million over the several years required to teach it to all school employes, if the loss of teachers' time is taken into account.