Chinese Communist Party Chairman Hua Kuo-feng wound up his historic Eastern European tour yesterday with a warm hug for his Yugoslav host, President Tito. It was a symbolic gesture of rapprochement between the leaders of the first two Communist countries to successfully challenge the right of the Soviet Union to depict itself as the center of world communism.

Hua's extraordinary visit has infuriated the Kremlin, established a Chinese interest in Eastern Europe and marked Chairman Hua's personal debut on the world stage. By common consent, the implications of the visit are considerable.

The visit, among other things, has been an educational experience for the new 57-year-old Chinese leader. The son of a peasant, he was brought up in the Chinese provinces and, apart from a visit to North Korea earlier this year, he had never been abroad.

Over the last two weeks, he has joined in the hora, the Romanian national dance, and seen such varied sights as a Roman amphitheater (in the Yugoslav coastal resort of Pula) and a long-haired youth plucking a guitar (at a cultural evening in Belgrade) - all no doubt, for the first time in his life.

For the journalists who were allowed to follow him around, film him, and even jostle him as he toured factories and attended concerts, one of the most fascinating aspects of the trip was to see Hua learn the tricks of an accomplished politican as he went along.

At first, he seemed shy and reserved. Unlike Western or even image-conscious Eastern European leaders, he made little attempt to shake hands or make contract with the huge crowds who turned out to greet him.

By the end of the tour, he was shaking hands vigorously in reeking cowstalls, making himself at home in a worker's apartment, interrupting the lenghty explanations of his guides with his own questions - behaving, in short, like a politican up for election.

At the same time, he became less self-conscious - or perhaps, as his exhausting itinerary ground on, he simply ceased to care. During a cultural performance in Bucharest, it was noticeable that he would swiftly remove his glasses whenever he realized he was being photographed. At a similar event later in Belgrade, he left them on and enjoyed the show.

By the time he reached Skopje, capital of Yugoslavia's republic of Macedonia, he had taken to smoking in public as well.

Since emerging from relative obscurity to succeed Mao as Chinese leader in October 1976. Hua has clearly become more concerned about his public image.Besides wearing a silver wristwatch, smart shoes and well-cut suits, he has dyed his greying hair black and has had his once-dirty fingernails well manicured.

With delicate hands and a pen in his breast pocket, Hua presents the image of the efficient communist functionary. When something interests him, his eyes narrow and he nods gravely. He is alert to what is happening around him: when he saw a rolling piece of machinery about to hit some photographers in Romania, he waved at them to move out of the way.

In talks with Tito, Hua made clear that this was merely the first in a series of tours he plans to make both to European and to non-European countries. France and West Germany have been mentioned as possibilities for the next visit.

Yugoslav officials who have had dealings with the Chinese believe this unprecedented interest in, and apparent desire to learn from, the outside world reflects a profound change in internal Chinese politics since the death of Mao.

The Yugoslavs say they have been amazed by the degree of detail with which Chinese delegations have studied their unorthodox system of workers' self-management. One effect of the system, under which power in individual factories is vested in the workers themselves, has been a general decentralization of decision-making and the introduction of a markettype economy.

The Yugoslavs believe the Chinese are considering similar reforms in order to achieve their goal of transforming China into a modern, industrialized society.

Hua could well return to China having learned a lesson in political flexibility from Tito. One of the qualities of Tito that Yugoslavs find attractive is that he has never been averse to other people sharing in the bourgeois comforts he himself enjoys so much. It is conceivable that Hua, after being entertained on Brioni in a style normally enjoyed by royalty, may now be prepared to soften some of the more spartan features of Chinese communism.

For the Chinese, the chief novelty of the visit was that it dramatically illustrated the opening of a new more outward-looking era in their foreign policy. Here, as in domestic policy, Hua has overturned the tradition set by his predecessor, Mao Tse-tung, who preferred to remain in Peking where he granted the occasional, highly prized audience to special friends.

His main preoccupation on this trip, however, is with outmaneuvering the Soviet Union, the country seen by Peking as its main enemy.

By his very presence in Yugoslavia and Romania on the 10th anniversary of the Soviet-led invasion of Czechoslovakia. Hua has succeeded in challenging the Kremlin in its own sphere of influence. What is more, he has succeeded in putting on record in Eastern Europe the Chinese view that aggressive Soviet policies abroad, particularly in Africa, pose a threat to world peace.

For Yugoslavia and Romania, friendship with China is a valuable counterbalance to their existing ties with the Soviet Union.

It has also strengthened the antimonolithic group within the world communist movement.

The Chinese have evidently dropped their attempts to depict Peking as a rival center of world communism to Moscow. Instead they are backing the view of the Yugoslav, Romanian, and Western European Communist parties who find common cause in the insistence that there can be many, very different roads to socialism.

Despite the usual rhetoric about the inherent value of friendship between peoples, Hua, Tito, and Romanian President Nicolae Ceausescu each had their own national interests at heart throughout Hua's trip.

As one senior Western diplomat in Belgrade remarked: "These three men are all hard-boiled politicans. For each of them, this has been a carefully calculated exercise. each independently reached the conclusion that the likely gains in terms of their own political prestige and freedom of maneuver that flowed from the visit outweighed the possible risks of a negative Soviet reaction."

Both the Yugoslav and Romanian leaders certainly had a clear idea of the reasons motivating Hua to honor their countries with the first trip by a Chinese Communist Party leader west of Moscow.

Asked about a Soviet press commentary suggesting that Yugoslavia was being seduced by China's "tactic of smiles," Tito's senior foreign policy adviser replied with a grin: "You don't think we are exactly naive ourselves, do you?"

For Tito, Hua's visit has been a notable personal achievement. It is the second time in his life that the leader of a country that once denounced him as a "traitor to communism" has come to Yugoslavia to bury the hatchet.

The first time was in 1955 when then-Soviet leader Nikita Khrushchev publicly apologized at Belgrade airport for "mistakes" toward Yugoslavia committed by Josef Stalin.

Yugoslav officials have confirmed that relations between the Yugoslav and Chinese Communist parties have now been fully restored - 20 years after they were broken off by Mao, who described Tito as the world's leading revisionist.

The main unknown factor about the visit, which makes its implications so difficult to gauge, is the reaction of Moscow.

Like the characters in a Chekov play who fall in love with glamorous strangers who drop in for a few days and then leave, both Tito and Ceausescu are now faced with the problem of how to mend their strained relations with their more usual partners - the Soviet Union, Bulgaria, and Albania.

In piblic the Soviet reaction has been predictably bitter. The Soviet news agency Tass accused Hua of trying to undermine the unity of the world communist movement and by implication criticized both Tito and Ceausescu for going along with his plans.

Bulgaria, which evidently now feels encircled itself, described the visit as "endangering Balkan peace."

What is at present impossible to predict is whether, and how quickly, the old uneasy equilibrium in the Balkans can be restored. Much depends on whether the Soviet leaders feel that not just their pride, but also their security is threatened by the new Chinese interest in the region.