The National black Political Assembly and the Commission for Racial Justice announced plans yesterday to hold a two-day conference at Howard University in March on the role of black Americans in the struggles of blacks in Southern Africa.

The purpose of the March 18-20 conference is to inform American blacks of the "background, historical development and present status fo the liberation struggles" in Southern Africa, to analyze U.S. policy toward Southern Africa and to rally black Americans to support black African liberation struggles, conference sponsors said.

"In spite of the increased publicity about Africa in the past several months, there has not previously been a meeting in which blacks in this country have discussed their responsibility to the political struggles in Southern Africa and discover ways to help in a unified and coordinated fashion," said Dr. Charles Cobb, executive director of the Commission for Racial Justice, in a statement.

Koko Farrow, a local leader in both sponsoring organizations, said although conference organizers hoped to attract a wide-range of black people, they would appeal primarily to black professional organizations and black churches to send respresentatives.

Jay Chunn, president of the National Association of Black Social Workers and Dr. Ron Walters, president of the African Heritage Studies Association appeared at yesterday's press conference in support of the March conference.

Ambassadors representing African nations in the U.S., plus representatives from the liberation movements in South Africa, Rhodesia and Namibia, the Organization of African Unity, and Caribbean countries will be invited to attend the conference, Farrow said.

The March conference will coincide with the commemoration of the March 21, 1960 Sharpeville Massacre where at least 62 black South Africans were shot and killed by South African police during demonstrations against that government's strict aegregation policy.