Vice President Bush's top black assistant declined to accompany him to Africa after other aides rejected his proposal to have several black Republicans go on the trip and selected a Democrat as the only black guest.

As a result, Steven J. Rhodes intends to resign as Bush's domestic policy adviser and leave the administration, several informed sources said.

The sources said Rhodes had presented a list of eight blacks, led by Republicans, to accompany the vice president on his tour of drought-stricken Africa. They included experts in agriculture and business development as well as the Democratic president of Meharry Medical College in Nashville, a black school kept alive in part by major federal grants from the Reagan administration.

But other Bush aides decided to take only persons on the vice president's staff and guests directly involved in African affairs.

"We did not want to make this into a political boondoggle," said a Bush staff member. "I'm not denying the inherent political value of going to Africa at a time when we [the administration] are interested in better relationships with black voters. But to pile on people who have never been to Africa, who know nothing about the drought situation, just because they are black and Republican would be wrong."

The only black, nongovernment official selected for the trip on the basis of his knowledge of Africa was C. Payne Lucas, 51, director of AfriCare, an organization that provides health care and project development to African nations. Lucas, a former Africa regional director for the Peace Corps, is a Democrat.

Rhodes refused to answer questions about the controversy, but, according to administration officials, he urged Bush a week before the trip to include blacks -- especially Republicans -- on the trip roster.

Bush reportedly told Rhodes to work out the problem with C. Boyden Gray, Bush's deputy chief of staff. When the final flight roster included none of the blacks or Republicans he had proposed, Rhodes reportedly told Bush he would stay home in protest and would cite a recent illness as the excuse.

In January, key black Republicans complained to Bush and top administration political aides that they had no access to the president or vice president and were not getting the same patronage and recognition that white Republicans were getting, despite their work for the president. Bush promised to try to include more black Republicans in White House events and not to include black Democrats in such functions unless black Republicans had a prominent role.

Meanwhile, the only other black policy aide on the president or vice president's staff -- Melvin L. Bradley, a special assistant to the president -- reportedly has come under increasing White House criticism for "ineffective" work with blacks.

According to the National Jour- nal, top White House aides be- lieve that Reagan needs to replace Bradley with a high-ranking black who has "greater persuasive skills than those demonstrated by Bradley."

In an interview, Bradley said he has not been asked to leave although his main link to the administration, Attorney General Edwin Meese III, no longer is at the White House.