Important elements of the Chinese government are attacking the secret police system in a new outpouring of wallposters and press articles calling for a landmark change in Chinese social and political life.

The new campaign, which includes the first direct attacks on the late Chairman Mao Tse-tung and many charges of police abuses after a 1976 demonstration, also seems to hint at trouble for the nation's leading internal security expert, Communist Party Vice Chairman Wang Tung-hsing.

Even a partial dismantling of China's internal surveillance network, which compiles secret dossiers on outspoken citizens and often makes midnight arrests, would have an incalculable effect on the daily lives and conversations of ordinary Chinese.

About once every 10 years the Chinese risk some public debate over the need to loosen the reins on free speech and to limit police power. It remains uncertain whether the latest outpouring will have more lasting impact than earlier unsuccessfual attempts to change the system.

In a particulary remarkable departure, the official People's Daily published a front-page article Monday by a "guest commentator" discussing Stalin's 1930s purge of Soviet Communist Party veterans and warning that similar miscarriages of justice in China would have to be reversed quickly to quiet "discontent and indignation of party and non-party people."

The article charged that Nikita Khrushchev, a favorite villian to Chinese editorialists, first supported the Stalin purges and then made use of the resulting resentment to take power after Stalin's death.

some analysts took this as a veiled swipe at Wang, who administered many of China's Cultural Revolution purges of the 1980s from his post as head of Mao's palace guard, then rose to the number five position in the leadership after Mao's death in September 1976.

For several months the Chinese press has been printing occassional articles recommending restoration of "socialist justice and democracy" after abuses in the late 1960s and early 1970s. But the latest campaign to rehabilitate hundreds of people arrested after a tumultuous demonstration in Peking's Tienanmen Square on April 5, 1976 has stimulated an outpouring of what appears to be genuine public sentiment. Wallposters have gone up in Peking asking for further investigation into the secret police procedure that led to the arrests. They also demand open trials and other reforms in the future.

As with all campaigns in China, such pleas for a more open society may in some cases be only devices used by one group to weaken the position of a political rival.

In this instance, veteran party bureaucrats without any deep commitment to due process may just be using a convenient stick to hit at security and personal officers who still hold files with unfavorable comments and information on their careers.

On Monday, the official organ of the people's Liberation Army, an organization that in the past has usually preferred social order to free speech, published one of the most outspoken defenses of the 1976 demonstration.

"The people wanted to break out of their ideological bondage," the Liberation Army Daily article said of the 1976 demonstration. "They wanted to enjoy the socialist democracy stipulated in the constitution and they opposed fascist despotism."

On April 5, 1976, about 100,000 people filled Tienanmen Square in the center of Peking to protest the hasty removal of wreathes commemorating the death of Premier Chou En-lai. Chou had been revered for supporting a raise in personal living standards and pardons for victims of past ideological campaigns, but party dogmatists led by Mao's wife, Chiang Ching, saw the pro-Chou sentiment as a threat and removed the wreaths.

Mobs that day attacked students who favored the Chiang Ching line, clashes with police broke out, and by the end of the day more than 100 people had been injured and several vehicles and one building had been burned. The official press disclosed for the first time last week that 383 people were arrested, all of them later cleared.

Posters put up in Peking in the last few days have demanded further satisfaction. Diplomatic sources in the Chinese capital say one poster, signed by an office of the Academy of Sciences, demanded an accounting of the number of deaths and public identification of the officials who labeled the demonstrators as counter-revolutionaries and ordered the arrests.

Identifying those responsible for the arrests might be embarrassing for the majority of the members of the Politburo that denounced the demonstration on April 7, 1976 and are still in power today. Some have rushed to endorse the new verdict on the demonstration, however.

New party Chairman Hua Kuo-Feng, whose position is particularly difficult because he was promoted right after the demonstration, wrote a special inscription for a new book of poems commemorating the Tienanmen incident.

Peking sources said they could not confirm a Japanese report that one new wallposter denounced the Hua inscription and said Vice Chairman Teng Hsiao-ping, who was purged for alleged support for the 1976 demonstration, should have had the honor of inscribing the book.

Vice chairman Wang, however, has so far made no public sign of endorsing the campaign to honor the demonstrators, whom his security forces probably had some hand in arresting.

Analysts have also suspected Wang to be in some difficulty because of attacks on the party journal, Red Flag, with which he is associated. The magazine has been attacked in at least one wall poster for failing to join enthusiastically in veiled criticisms of Mao's attempts to prohibit houses for factory workers and deny university places to children of intellectuals.

Wang, who served for years as Mao's personal bodyguard, is more closely associated with the late chairman than any other member of the current leadership.