Within hours after completing three days of talks with U.S. officials, China picked up its "Russia card" today by calling for negotiations with Moscow to settle the volatile Sino-Soviet dispute.

In the most conciliatory Chinese move in two years, the Communist Party newspaper People's Daily published a long article proposing that both sides withdraw troops from the heavily armed border and begin talks aimed at a new treaty to demarcate the contested boundary line.

While the article was seen as a true reflection of Peking's interest in settling the border problem, diplomats said its publication on the day that Secretary of State Alexander M. Haig Jr. ended his official visit here suggested that the message was directed at least as much at Washington as Moscow.

Diplomats here viewed the article as a warning to Washington that despite the new U.S. decision to sell weapons to China, Peking is not ready to commit itself to an anti-Soviet alliance with the United States until the delicate issue of U.S. arms sales to Taiwan is settled.

As the diplomats interpreted the article, the party's official newspaper publicly put U.S. officials on notice that even though China proved flexible enough during the recent talks to allow bilateral relations to progress without resolution of the Taiwan issue, there is a limit to Peking's patience.

During Haig's visit, Chinese officials strongly state their opposition to the Taiwan weapons transfers, arguing that the U.S. arms sales embolden Taiwan's Nationalist Chinese leaders to resist China's efforts to peacefully reincorporate the island as an integral part of the country.

For weeks before Haig's arrival Sunday, Peking criticized the arms sales as a violation of the 1979 treaty establishing full Sino-American diplomatic relations in which Washington recognized Peking as the sole legal government of China and designated Taiwan as a part of China.

The talks failed to molify the Chinese side as indicaed by Foreign Minister Huang Hua's farewell banquet toast last night. Huang, noting differences between the two nations, emphasized that the "cornerstone" of Sino-American relations is the 1979 normalization treaty.

"Not only must we protect this cornerstone with great care," said Huang, in what diplomats interpreted as both a challenge and a warning to the U.S. guests, "we must also prove with our actions that it can stand tests. This point can never be overstressed."

Huang chose not to see Haig off at the airport today after President Reagan said in Washington yesterday tht he still had friendly feelings for Taiwan and intends to "live up to" the law allowing the United States to sell defensive weapons to its old ally, Taiwan.

The Taiwan ingredient in Sino-American relations has proved to be a difficult stumbling block for the Chinese, who otherwise feel very comfortable with the Reagan administration's hard-line stance against the Soviet Union, which has more than 500,000 troops stationed along China's northern border.

Chinese leaders worry, however, that the new administration believes Peking will tolerate an upgrading in U.S. relations with Taiwan and continued arms sales just because of its strong anti-Soviet policy. Peking has taken pains to say that it would not tolerate such a trade-off.

The People's Daily article today proposing to pacify the hostile Sino-Soviet border was seen here as a signal to Washington that China has other diplomatic options to consider as long as the United States still talks about upgrading relations with Taiwan and about considering Taiwan's request for an improved fighterr plane.

Diplomats said the timing of the article was much more significant than the specific proposals, which have been put forth by the Chinese in past diplomatic efforts to settle the 17-year boundary quarrel with the Soviet Union that has resulted in sporadic armed clashes and frequent bickering.

The People's Daily said, "It is known to all that the past more than 10 years have witnessed a heavy Soviet military buildup in areas bordering China, the deployment of a growing number of offensive weapons, the establishment of command headquarters and endless military exercises and other military activities spearheaded against China. All this constitutes military threats against China."

The last time the Chinese offered to negotiate the dispute along the 4,500-mile border was in 1979 when Peking suggested an overall normalization of relations with the Soviet Union. After a single negotiating session, China called off the talks in January 1980 after Soviet troops invaded Afghanistan.

Although ever suspicious of Soviet intentions to encircle it, China would like to lessen its costly commitment of an estimated 1.5 million troops along the northern border, according to diplomatic and military analysts. China is said to have another 250,000 troops stationed in the south on its border with the Soviet Union's ally, Vietnam.