The 33 Commonwealth nations broke precedent today and condemned the "massive violation of human rights" in Uganda.

The communique does not name the country's leader, Idi Amin, but takes the unprecendented step of citing Uganda by name.Never before in its 30-year history as a multiracial organization has the Commonwealth publicly denounced one of its members.

Moreover, the move was led by several of Amin's fellow black African leaders.

The Commonwealth - Britain and its former colonies - has no substantive power, so today's resolution carries only moral force at best. But the step could provoke action against Amin inside Uganda, as Australian Prime Minister Malcolm Fraser observed.

"If it is known that the leaders of 1 billion people are morally opposed to Amin Dada, this could contribute the toppling of his regime," he said.

Today's communique says:

"Cognizant of the accumulated evidence of sustained disregard for the sanctity of life and of massive violation of basic human rights in Uganda, it was the overwhelming view of Commonwealth leaders that these excesses were so gross as to warrant the world's concern and to evoke condemnation by heads of government instrong and unequivocal terms . . . Heads of government in looked to the day when the people of Uganda would once more fully enjoy theri basic human rights, which now were being so cruelly denied."

The word "overwhelming" underlines that the denunciation was not unanimous. The dissenters were not made punlic, but in the course of the eight-day meeting, Malawi, Nigeria and Prime Minister Morarji Desai of India made it clear that they were opposed to the move.

Traditionally, Third World leaders have refrained from criticizing one another on the ground that no natin should interfere in the affairs of another. This doctrine has been convenient to may third World totalitarian states, left and right, that have violated individual rights.

But as British Prime Minister James Callaghan told teporters, Amin's Uganda is a special case. "There has been a quantum jump" in atrocities there, he explained."The excesses were so gross."

Amin is thought to have ordered the killing of tens of thousands of his own people and sometimes done the killing himself. Two Ugandan refugees in Nairobi told a British television reporter yesterday that Amin conducted a ritual killin of a former minister, drinking his victim's blood to ward off a haunting spirit.

Today's unusual action also strengthens the Comminwealth's regular attacks on the white regimes in Rhodesia and South African foes by asserting that they subscribe a double standard of morality. Now that argument has lost some force because blacks have condemned outrages committed by a black ruler against his black subjects.

The fight for a strong denunciation was led inside the meeting by President Kenneth Kaunda of Zambia, whom Amin is continually threatening with war. As the conference began last week, Kaunda was calling Amin "an essentially evil man" whose "atrocities [are] unequaled in the history of the Commonwealth."

The one concrete measure taken at the meeting assures that the Commonwealth track and field meet will be held next year in Canada. The Africans had threatened to boycott the games because of New Zealand rugby team played in South Africa. This same issue had kept most African nations out of last year's Olympics.

New Zealand Prime Minister Robert Mouldoon joined the others in agreeing to "discourage" competition with South Africa. Th For now that has satisfied everybody and the boycott has been lifted.

The bulkiest section in the long Commonwealth communique is taken up with attacks on the "racist" regimes of Rhodesia and South Africa. The leaders urged the international community to start an immediate embargo on supplying arms to South Africa and denounced South Africa's continued presence in Namibia. And they particularly hit at the oil flowing to the "illegal" Rhodesian government.

Much of this vital oil is believed to come form the South African affiliates of British Petroleum and Royal Dutch Shell. The British government owns 51 per cent of BP and British private interests own nearly half of SHell.

Callaghan said his governmnet is looking into this but indicated that not much would be done. South African law, he explained, prohibits local firms from disclosing shipments to Rhodesia. Callaghan suggested that his government would be helpless to force BP and Shell to come clean.

The fact that Britain has $1.7 billion of direct investment in South African plants could be another reason for not pressing too hard.