One of Peking's most controversial underground journals has reappeared along with a new surge of demonstrations and uncensored attacks on police tactics which signal a return to the freewheeling pro-democracy protests of a year ago.

The reappearance of the journal Tansua (Exploration), official concessions to sitdown demonstrators here and veiled apologies in the press for last spring's crackdown on dissidents have led many Chinese and foreign diplomats here to predict even free expression and the release of some jailed protesters.

"The drift everywhere is toward more sympathy to this kind of dissent and they have to face a decision whether they are going to release these people or keep them in jail," said one longtime-resident pointing to the new criminal code which seems to rule out arrests of people who simply criticize the government.

Although very small in numbers, the Peking dissidents have through exposure in the foreign press made themselves an important element in world perception of the situation here with some effect on future Chinese trade and political successes abroad. This is particularly true in Western Europe which Communist Party chairman Hua Guofeng plans to visit next month. Treatment of the few dissidents also sets the standard for treatment of much more explosive protests by unemployed youth and destitute peasants who have besieged offices here and in other Chinese cities.

The scene Sunday at Peking's "democracy wall," the wallposter area that since the April crackdown has seen only muted attacks on the government, reminded many Chinese here of the most lively days of last autumn's democracy movement.

A staff member of the revived journal Tansuo put up a poster demanding the release of the journal's editor and other dissidents. Plainclothes police snapped his picture with brand new Nikons and a young man describing himself as staff photographer for the dissident journal snapped their picture in turn. Later at least 400 students marched down Peking's main avenue protesting the admission of several students to universities through political connections and the official press acknowledged that many demands by peasants organizing a sitdown protest recently were justified.

Diplomats here caution that the government could again arrest some of its strongest citizen critics and swiftly dampen the atmosphere. But Chinese here say that officials, sharply divided over how to handle the protests, are not expected to act harshly soon. Peking's Communist government celebrates its 30th anniversary Oct. 1, a time for pointing to progress in higher living standards and more free choice. Hua's trip to Britain, France and West Germany follows soon after. China's steadily growing ties with the United States may also work in the dissidents' favor. Some diplomats noted the new upsurge in free expression coincided with Vice President Mondale's recent visit and recalled a State Department expression of concern during the earlier spring crackdown.

"Where there is international press attention, they feel also they are protected, but there is also some danger in this," said a resident who has met several of the dissidents. "Back in November they competed to see who could come up with the sexiest idea on a wallposter so they could hear themselves quoted on the Voice of America."

Such excesses, including some wallposters calling for the end of Communist Party rule, resulted in the arrests of about 28 dissidents, including Exploration's editor Wei Jingsheng, deputy editor Yang Guang, human rights alliance leader Ren Wanding, and a female dissident, actually the first to be arrested, named Fu Yeuhua. Some foreign diplomats here do not think the term dissident applies well to many of the wallposter writers, because at the beginning, they feel many of the attacks on government leaders were encouraged by other government leaders -- such as Vice Premier Deng Xiaoping -- who saw the wallposters as a way of undermining political enemies.

But Wei, Ren and the others appeared to strike out on their own very quickly, and one unconformed report circulating here said Deng personally approved their arrests.

For a while, contacts between dissidents and foreigners ended, and dissidents who remain free do not dine at journalists' apartments very often any more. But conversations between foreigners and Chinese who visit the wallposter wall along the Avenue of Eternal Peace are now freer and more frequent. Over the last two months, far fewer controversial posters have been torn down by the midnight government censors who used to visit the wall nightly.

The official press, including the authoritative People's Daily, has now begun to upbraid the police who arrested the dissidents in March and April. The People's Daily this weekend reported what appeared to be a self-criticism by one leading police officer. The paper advised policemen to put aside feelings that they were now "hamstrung" by new laws that forbid arresting people just for speaking out against the government.

As a significant sign of the new policy, the authorities pardoned and gave a good office job to a former editor of one underground journal, Reference News for the Masses. The editor, Xia Xungian, had been ordered back to his native Hunan Province during the crackdown. His new job is also in Hunan.

"What with all the press discussion in the direction, and with Hua's trip to France [where Agence France-Presse's extensive coverage of the dissidents has had particular impact], there is a slim chance that they might release the rest of the people from jail," said one European diplomat.

Perhaps the dissident working most actively for their release is Lu Lin, a staff member of Tansuo who was questioned by police in March and April but released. His latest wallposters demanding freedom for dissidents include his version of conversations with police authorities to whom he has presented his demands. "Those people were arrested as counter-revolutionaries," he said he was told. Chinese officials are now openly debating whether the term can be applied to people who only speak, not act, against the party. "The police are watching you," Lu said he was told. "Next time you put up a poster, you must call us and tell us you are going to do it."

Many of the dissidents are now reportedly kept in detention center No. 44 here, a temporary holding area that indicates no final decision has been made in their cases. Wei and Yang have allegedly been accused of unauthorized use of an office truck to take leaflets to Tianjin, but the truck driver has reportedly defended them, saying he signed the truck out. Earlier, officials indicated that some of the dissidents would be tried for passing secret documents to foreign diplomats. Although some diplomats were offered such documents several months ago several diplomats have compared notes and concluded, one said, that "none of the people in jail did anything like that."