China has agreed to boost trade with Poland by about 30 percent this year, apparently ignoring President Reagan's appeal for economic sanctions against the Polish government for imposing martial law.

Some diplomats view the trade protocol and Peking's refusal to condemn the Polish government as tacit Chinese approval for the crackdown on the kind of labor strife that one day could surface in China.

"The picture of a communist government being overthrown by workers obviously disturbs a lot of Chinese leaders," said a Western diplomat.

Other foreign analysts believe the trade pact signed eight days ago had nothing to do with martial law but was part of Peking's continuing effort to expand economic relations with all East European countries.

Chinese officials who met with Western diplomats this week continued to stress China's neutrality on the Polish crackdown and downplayed the trade agreement as "a routine thing," said a foreign analyst.

"There was no intent to snub Reagan," insisted a European diplomat. "Peking has its own domestic considerations, and it is serious about maintaining an independent and noncommittal posture on Poland."

China agreed under the $140 million trade pact to provide food, consumer goods and textiles to the beleaguered Poles, according to an East European envoy, who said exchanges will rise between 25 and 30 percent during 1981.

The new agreement, however, falls far short of replenishing the 55 percent drop in trade between the two nations last year as compared with 1980, the diplomat said.

Publicly, Peking has held to a neutral course on the Polish crisis, calling on the Poles to settle their own problems and opposing outside intervention by the Soviets or the West.

Chinese officials who normally are very critical of Soviet diplomatic adventures studiously have refused to join Western nations in blaming Moscow for the crackdown in Poland.

Privately, Chinese officials say they are unclear how much responsibility Moscow bears for the imposition of martial law.

Three weeks after ordering economic reprisals against Warsaw, Reagan dispatched Assistant Secretary of State John Holdridge to Peking in part to enlist Chinese cooperation in the sanctions drive, according to informed diplomats.

Holdridge, whose chief mission was to explain Reagan's controversial plan to sell military aircraft to Taiwan, discussed the issue with Chinese officials but failed to inspire much interest from Peking, the diplomats said.

Recently, East European diplomats have touted the Polish trade pact as Peking's "answer to Washington," both defying Reagan on the sanctions effort and showing displeasure over the sale of aircraft to Taiwan.

These diplomats view China's handling of the Polish matter as evidence of a general move to soften its confrontation with the Soviets supported by Peking's secret proposal to double trade with Moscow this year and increase cultural exchanges.

Other diplomats called this wishful thinking by Soviet allies who are trying to undermine Chinese-American relations at a sensitive time when the two sides are seeking a compromise on the issue of arms sales to Taiwan.

Foreign analysts believe the East Europeans are trying to fan anti-Chinese sentiment in U.S. policy circles by planting stories that could portray Peking as an unreliable American friend willing to court the Soviets as a protest over Taiwan.

With Peking pushing for a compromise on the issue of arms sales to Taiwan, Western analysts see little evidence that it is trying to use Poland as a lever for gaining concessions from Washington or for venting its resentment.

Nor is there much to support claims of a possible Sino-Soviet rapprochement with the official Chinese press continuing to flail at Soviet aggression in most corners of the globe except Poland, said the analysts.

Chinese officials moved this past week to assure Western embassies in Peking that a recent 10-day visit by Sergei Tikhvinsky, deputy chairman of the Soviet-China friendship association, included no substantive talks.

A well-informed diplomat from a nonaligned nation confirmed that Peking has proposed broadening trade and cultural exchanges with the Soviet Union, but he cautioned that this is designedmore for public relations than strategic considerations.

Even the doubling of Chinese-Soviet trade that has been proposed by Peking to increase timber supplies from the Soviets would leave overall bilateral exchanges a fraction of Chinese-American or Chinese-Japanese trade, he said.

"China wants to develop socialism at home and can't afford to cut itself off from the rest of the socialist world," he said. "If they can't balance their strategic relations, they at least can balance their economic and cultural ones."

"But they still make it plain that the one superpower that is the main threat to world peace is the Russian one," he added.

Earlier this year, Peking turned down a Soviet bid to resume negotiations on their contested common border, which has remained the flash point of Chinese-Soviet relations since the two communist giants fought over a small section in 1969.

Apart from the Soviet Bloc, most diplomats in Peking believe China's view of the Polish crisis has been dictated by domestic Chinese factors, not its relations with Washington or Moscow.

After scattered labor strikes hit Chinese factories in late 1980, including some calling for independent Polish-style trade unions, Peking stopped publicly supporting the Solidarity independent labor movement.

The Chinese inevitably view their own position as potentially parallel with Poland, where the ruling Communist Party lost prestige among its own people, according to Chinese sources.

Some Chinese officials reportedly are uneasy with Western support for a dissident labor organization, such as Solidarity, inside a communist society where trade unions are normally controlled by the party.

"The basic Chinese view is they don't want little Solidarities popping up in Peking or Wuhan or anywhere else in China," said a Southeast Asian diplomat. "Their motivation is fear."