The visit by China's top leader to North Korea and a high Chinese delegation's tour of Western Europe have raised expectations of major new Peking Diplomatic initiatives, but events so far seem to suggest just more of the typical post-Mao Chinese caution.

Chinese Communist Party leader Hua Kuo-Feng's train journey last week to neighboring North Korea, the first time that Hua is known to have left China, illustrated Pekings great confidence in one of its warmest longtime allies.

In North Korea, Hua can test his diplomatic wings without any fear of encountering hard questions or difficult situations. At the same time, he can flatter the Koreans with his presence and keep them from edging too close to Peking's Soviet adversaries.

Observers in Asia and United States have suggested that Hua's trip might be the start of a complex effort to get talks on Korean reunification under way, since U.S. national security adviser Zbigniew Brzezinski and Romanian President Nicolae Ceausescu - a useful middleman - are due in Peking later this month.

Although Asian and European analysts her think South Korea has come up in Hua's talks with North Korean President Kim II Sung, they see little Chinese desire or ability to organize a North Korean South korean detente right now. "They would have to get the North Koreans to make some concessions, and that would ruin the whole atmosphere," said one analyst.

In Europe, a visit by Chinese Vice Premier Ku Mu and his 20-member delegation has stimulated great curiosity, particularly after news reports here and in Tokyo suggested that the Chinese had made their first major purchase of Western arms in a deal for French antitank weapons.

A pro-Peking newspaper here had printed a Japanese report of the deal on its front page, which some analysts took to be a confirmation of the purchase, but French officials entertaining Ku's party later said they were not aware of any major arms deal with Peking.

Premature reports of major Chinese purchases occur regularly, because the Chinese are voracious windowshoppers. By showing great enthusiasm for all kinds of western equipment, they are able to gather a great deal of technical information without actually signing any contracts. Ku's team is spending 10 days in France, visiting nuclear power stations among other things, and then is scheduled to move on to Switzerland, Denmark and West Germany.

Another Chinese group is in Britain and a military team recently visited airplane, helicopter and missile manufacturing plants in France.

The Japanese Kyodo news service had reported that Chinese Deputy Chief of Staff Wu Hsiu-chuan, in Peking talks with Japanese military affairs specialists, revealed a Chinese agreement to purchase French HOT antitank missiles and related technology, the deal French officials say they are unaware of. The Chinese need to overhaul their tank corps to have a chance of stopping any full-scale Soviet invasion. Antitank weapons would go along with that effort.

French officials say the Chinese have also expressed interest in the Milan antitank system, the Exocent ship-to-ship missile and the Crotale weapons system against low-flying jets.

Peking's top foreign policy problem, what it perceives as the Soviet threat, undoubtedly has taken up part of Hua's conversations in Pyongyang - even if in his public statements he has softpedaled his usual anti-Soviet rhetoric in deference to Kim's continued relations with Moscow. Hua is thought to have argued for North Korea's support in China's continuing propaganda duel with Vietnam.

Chai Tse-min, the Chinese diplomat due to head Peking's office in Washington, told a banquet this week in Bangkok, Thailand, that China had to protect overseas Chinese, a thinly veiled reference to the harsh treatment being meted out at the moment to ethnic Chinese in Vietnam.

On Sunday, Hua delivered the ritual attack on the U.S. presence in Korea and what he said was the U.S. desire to "freeze and perpetuate the division of Korea." Analysts are confident, however, that the Chinese will work quietly to keep the Peninsula calm, even if it means continued U.S. troop involvement, so that the Soviets have no chance to become more involved in Korean affairs.

One Japanese diplomat recalled Kim's quick trip to Peking in 1975, when many speculated that the North Koreans were about to launch an offensive against the south." We have no such worries now," he said.