Harvard students must join in the fight against racism in order to help prevent further outbreaks of anti-busing violence, a black leader from Roxbury said yesterday.

Reverend James Coleman of the Concord Baptist Church in Roxbury, in a speech to a small group of faculty and students at Phillips Brooks House last night, asked students "to get involved to rise up in indignation when peoples' rights are violated."

Coleman's home was fire-bombed by anti-busing terrorists last week immediately after Federal District Court Judge W. Arthur Garrity's decision to place South Boston High School in receivership.

Busing foes have also set fire to Coleman's church twice in the last month, causing nearly $700,000 in damage.

"Unless someone has the guts to speak up and provide leadership, the vio ence will continue," Coleman said yesterday. "Some ideals are worth death itself," he said.

Coleman briefly outlined what he called "the historical machine of oppression" of blacks in the United States.

"There has been a conspiracy to repress and kill outstanding black leaders. The Rev. Dr. Martin Luther King's murderers may not have been brought to trial," he said.

Help Offered

The Harvard-Radcliffe Committee Against Racism and Harambee, a black organization at the Divinity School, sponsored Coleman's talk. "We've offered him help and our full support," a member of CAR said yesterday.

Although he barely escaped death when the fire bomb exploded in his home office, Coleman insisted he is not bitter and expressed his faith by reciting "The Battle Hymn of the Republic."