President Carter believes that United Nations Ambassador Andrew Young was right when he said on Jan. 31 that Cuban troops "bring a certain stability and order" to Angola.

In his first public comment on the subject, Carter told a group of visiting editors, "I read the whole text, of course, of Andy's statement and what he said I do agree with it. It obviously stabilized the situation."

But the President appeared to disagree with Young's statement on Friday that the South African government is illegitimate. South Africa, the President said, "has a legally constituted government" and it "is a stabilizing influence in the southern part of that continent" and has a "major role to play in the peaceful resolution of Rhodesia and Namibia."

The President also told the editors:

The United States has been keeping China informed about "our basic positions" discussed in arms control talks with the Soviet Union.

Vice President Mondale has been given special responsibility for evolving a new policy toward Africa.

Mandatory quotas or high tariffs will be put on shoe imports if voluntary cutbacks do not work.

Any policy for dealing with illegal aliens has to contain "some element of amnesty" for some of those already in this country.

Two days after Young said in an interview: ". . . There's a sense in which the Cubans bring a certain stability and order -- to Angola, for instance . . .," the State Department officially took issue with him.

In a Feb. 2 statement that seemed to fall somewhere between a clarification and a reversal, spokesman Frederick Z. Brown said, "Neither Ambassador Young nor the Secretary [of State Cyrus R. Vance] condones the presence of Cuban troops in Angola."

In his interview with the editors, which was held Friday and not generally released until yesterday, Carter said he thinks the current Marxistoriented angolan government "is likely to stay in power. The Cubans ought to withdraw their forces from Africa."

Asked if such a withdrawal would be a precondition of normalized relations with Cuba, Carter did not give a clear yes or no.

"I would rather not say that before we ever had normal relations with cuba they would have to withdraw every Cuban from other nations on earth," he said. "We don't do it . . . But the withdrawal of Cuban troops is a dominant factor in angola and other places around Africa . . .

"I would rather not be pinned down so specifically on it. But the attitude of Cuba to withdraw its unwarranted intrusion into the affairs of Africa and other nations would be a prerequisite for normalization, yes."

The President's remarks on China were reminiscent of the Nixon-Kissinger triangular diplomacy, which involved using openings to China as a pressure point in negotiations with the Soviet Union.

"I have met with the Chinese special representative here . . . for an estended conversation," Carter said. ". . . We try not to violate confidences.

"If the Soviets tell us something in a negotiating session which we consider to be of a confidential nature we certainly don't tell the Chinese about it. But we tell them our basic positions. I think we have as good a relationship as one could have with China short of full diplomatic relations."

Vance has met with the Chinese special representative once since he returned from arms control talks in Moscow last month. Carter said.

Asked whether the Carter administration has "a definitive policy toward Africa as of yet," the President said. "We are evolving one" but added that "we have deliverately decided, as part of that policy, to let the British government retain the leadership role, for the time being."

The United States is "prepared to participate for the first time in a geneva conference if one can be called," Carter said.

"The difficult question is, you know, how much to push the South African government and drive them into a corner that alienates them from us, because to a major degree the South African government is a stabilizing influence in the southern part of that continent and they have a major role to play in the peaceful resolution of Rhodesia and Namibia."

A spokesman for Mondale said the Vice President received the africa policy assignment about a month ago and has since been holding regular meetings with administration Africa policy experts, including Young.

On illegal aliens, the President said some "have been here 15 or 20 years. They are fine American citizens in the practical sense of the word 'citizen.' They have good jobs, they are self-supporting, and we don't want to kick them out."

Some element of amnesty will be "mandatory," he said, "but I think the definition of amnesty is the difficult part."

On shoe imports, Carter on April 1 rejected high tariffs to protect the American industry, deciding instead to try to negotiate voluntary quotas with South Korea and Taiwan.

If they do not agree to cut back voluntarily, Carter told the editors, "then we will put mandatory quotas on them orhigh tariffs."