China's official news agency, in a sharp break with previous Chinese Communist practice, reported today an actual debate in its parliament on the subject: "Are there political prisoners in China?"

A New China News Agency dispatch outlined arguments by Liaoning University professor Sung Zexing against a new criminal code that seemed to require jail sentences for wallposter critics of the government. Public references to political prisoners in China in the past have been extremely vague and have involved no open debate.

The agency report appeared to be part of a major effort to portray China as a more democratic society than in the past and its parliament, the National People's Congress, as a body with actual influence in a state run by the Communist Party.

The debate report came one day after Chinese officials allowed U.S. Health, Education and Welfare Secretary Joseph Califano to make an unusual visit to the 2,600-inmate Shanghai city penitentiary. Califano was told that the number of prisoners held there for politically related offenses -- what the Chinese call reactonaries or counter-revolutionaries -- had declinded from about 70 percent to 7 percent in last 25 years.

The news agency report of the Congress debate, which also included a discussion of wife-beating, never referred directly to an estimated 20 youthful critics of the government who reportedly have been arrested in the last six months for publishing wall-posters and underground magazines.

Even Sung was not reported as saying there actually were political prisoners in China, only that "some of the provisions of the draft [criminal code] implied that there were" because they seemed to make wallposter writers subject to imprisonment.

The agency said that during the "keen debates" Sung "recalled the days when Lin Biao and the Gang of Four [former party leaders] could label anyone a counter-revolutionary for criticizing their misdeeds."

He said it was "necessary to add a clause to the criminal law specifying that it was strictly forbidden to define ideological and political problems as counter-revolutionary offenses."

He reportedly objected to a clause saying "anyone inciting others to resist or sabotage the implementation of any law or decree and anyone making propaganda using such things as counter-revolutionary posters to incite others to overthrow the dictatorship of the proletraiat" can be jailed.

"Such persons should be regarded as belonging to the category of political prisoners," Sung argued, according to the agency.

"His idea was rejected by several other deputies. They said that there were no political prisoners in China bcause a person could be held as a counter-revolutionary only when he had committed counter-revolutionary action."

Song Guany, mayor of Shenyang, said the phrase "or counter-revolutionary purposes" cleared anyone who was not seeking to overturn the party and the revolution. Their critiques could be resolved "through criticism and education," rather than jail, he and education," rather than jail, he said.

In his prison visit, Califano ignored an official warning about taking to prisoners and struck up conversations with several in a prison hospital ward.

In one bed he found a genuine reactionary, a 34-year-old sailor who said he was arrested in 1972 for attempting to spy for the National Chinese government on Taiwan. The man, who did not give his name, said he sailed from Hong Kong to Shanghai on a freighter with orders to gather information on China's Cultural Revolution.

Serving a 15-year sentence, he said he now "realized I did many bad things," and only wishes to return to Hong Kong.

Commissar Huang Bing showed Califano through several work rooms of the massive brick prison in a busy neighborhood. Prisoners covicted mostly of theft and other common crimes made shirts or watches. Their heads were shaved for "identification" but they appeared healty.They slept on straw mats in seven-by four-foot cells.