After a discussion punctuated by cries of "injustice" and "racism," the Montgomery County school board decided last night to postpone action on a proposal to eliminate a requirement that all school employes must take a course in black culture.

Board President Marian Greenblatt threatened to clear the auditorium at school administration headquarters following the outbursts of shouting from black parents who protested that they were not allowed to participate in the board's discussion.

George Sealey, president of the Montgomery County NAACP, told the board: "This course represents over 10 years of active dialogue with the black community. We will not stand by and let you undo the small amount of progress that has been made."

At issue was a resolution that would rescind the mandatory aspects of the course, which the board initiated in 1974 for all teachers and other school employes. The course consists of 15 weekly three-hour sessions and is intended to establish better understanding between staff and black students.

During their recent campaign for office, the school board's three newly elected members, Joseph Barse, Eleanor Zappone and Carol Wallace, and incumbent Greenblatt argued that the course is a waste of taxpayers' money and lowers morale of school employes, many of whom have expressed anger at having to take it. The three newly elected members plus Greenblatt form the board's new majority.

Three percent of the students in Montgomery County schools are black.

At one point last night, Zappone said the recent election represented a mandate for policy changes including change in the black culture course.

Board member Blair Wing, who voted against rescinding the course along with Elizabeth Spencer and Daryl Shaw, said, "If we pass this thing, it will do more damage to children than any other action I've seen in the 10 years I've been associated with this board."

Barse defended the move, calling it "only a technical change in implementation, not a change in major policy." His remarks drew boos and jeers from the crowd of about 150 that overflowed the auditorium. About half the crowd was black, but a majority of the audience appeared to object to the plan to strip the course of its mandatory feature.

After the decision to postpone a decision until Jan. 9, Greenblatt called a five-minute recess and left the auditorium with the other conservative members to a barrage of jeers.

"We only wanted to demonstrate our involvement in the planning process," James Moone, head of the Montgomery County Black Coalition, told a reporter. "We will not be silenced."

Braxton Boyd, a member of the school system's minority relations monitoring committee, said the board did not consult with the committee before drawing up last night's resolution.

But Greenblatt defended the exclusion of the audience from participating in the d i s c u s s i o n as a "normal procedure. We don't have to talk to everyone in the community in order to take action."

She repeatedly rapped her gavel on her table during the meeting, saying, "We are elected officials and this is a public meeting."