The next round of Sino-Soviet talks to improve long embittered relations will be held in early February, after U.S. Secretary of State George P. Shultz visits China, according to a senior Chinese official.

The official said Peking will send a high-level delegation to Moscow after the lunar new year in mid-February to resume consultations aimed at lessening tensions between the neighboring communist rivals.

That means China's leaders will first have a chance to hear from Shultz, who is scheduled to arrive Feb. 2 in the hope of restoring momentum to Sino-American relations that have faltered in the past 18 months over U.S. arm sales to Taiwan.

It is unclear whether the Chinese intentionally timed the Moscow talks to follow consultations with U.S. officials, who are wary about the strategic consequences of a possible Sino-Soviet rapprochement.

Peking, which has insisted it never will play its "Russian card," says any normalizing of relations with Moscow is a natural process for neighbors and should not be seen as a threat to other nations.

Yet, some diplomats believe China has softened its once harsh anti-Soviet stance partly to extract concessions from Washington. Peking would like a quick halt to U.S. arms sales to Taiwan despite the stated U.S. commitment to the island's defense.

Chinese and Soviet vice foreign ministers met six times during October in Peking to discuss ways of bettering relations. Except for agreeing to meet again in Moscow, they are said to have made no progress on the strategic issues dividing their nations.

However, the diplomatic climate has warmed since the death last month of Soviet leader Leonid Brezhnev. That provided Peking an opportunity to send its foreign minister to Moscow for the funeral and for consultations.

Returning from Moscow, then-foreign minister Huang Hua, who had conferred with his counterpart in the highest level meeting between the two communist powers in 13 years, said he was optimistic about the next round of talks.

The perceptible thaw in relations was evident again today when Peking sent Huang, now a state councilor, and Politburo member Ulanhu to the Soviet Embassy celebration of the 60th anniversary of the founding of the Soviet Union.

In past years, similar events at the Russian compound in Peking were not attended by high-ranking Chinese officials.

Chinese authorities will be invited back to the embassy within the next week to watch a performance of four Bolshoi theater stars who are in China as part of the anniversary celebration.

The performers -- three opera singers and a pianist -- will not be seen by the Chinese public, which was regularly treated to Bolshoi acts when Sino-Soviet relations were close in the 1950s.

Soviet sources said the ambassador had suggested that the small Bolshoi group play publicly or visit artists' workshops in Peking. But Chinese officials apparently scotched the proposal because the two nations have no official cultural agreement.

The second round of talks now planned for after the lunar new year, which occurs Feb. 13, is expected to discuss possible cultural exchanges as well as sporting and academic links, according to informed diplomats.