About once a month, whenever the latest issue of his sometimes acerbic, unauthorized magazine rolls off the hand mimeograph, Xu Wenli takes a copy and gives it to his unit leader at the Peking Railway Bureau.

The man accepts it without comment, and the 36-year old Xu, on paid sick leave from his job as a light fixture repairman, goes back to his tiny cubicle to compose another gentle manly attack on Chinese governement trials of political critics.

So goes, as it approaches its first anniversary, China's odd, contradictory democracy movement. It resembles an intricate but polite badminton match between the government and its critics -- eyeing each other suspiciously but observing makeshift rules that keep a form of free discourse flying back and forth.

It is, Xu admits, a situation very different from the harsh adversary relationship between dissidents and the government in countries like the Soviet Union or Chile. "Our position is different from that of China's national leaders," Xu said. "We are at the grass-roots level while they are at the leadership level. We look at problems from different angles but we hope that we can cooperate with them by supervising each other in our common effort to solve the problems of China."

The government critics here are not members of a disadvantaged ethnics group, like Jews in the Soviet Union. They are Chinese just like their leaders, and to an extent they share the Chinese instinct for keeping disputes in the family. They emphasize their mutual commitment to what may be one of the most homogenous and self-centered nations on earth. Some critics here like Xu are old enough to remember that in the past 20 years, during the era of Mao Tse-tung, critics who became too vehement were sent to labor camps. The controversial 15-year sentence given to one unofficial magazine editor last month may help to keep dissident voices low.

Xu's magazine, the "April Fifth Forum," began publishing last November, soon after the government signaled a new tolerance for dissent by clearing all those who had been arrested during an antigovernment riot on April 5, 1976. Sometime later police came to the tiny editorial office in an apartment building near Baiguang Road "to take a look and made an inspection," Xu said.

"In some respects they exceeded the scope of ordinary inspection, asking all present their names, addresses and work units," he said. "We hope this error was the work of a local police official with insufficient understanding of the political situation, rather than the . . . intent of senior party leaders."

"Explorations," the dissident journal edited by Wei Jingsheng, who received a 15-year jail sentence last month, appears to have stopped publishing at least temporarily. When I tried to find its most active editor still at large, Lu Lin, his mother told me he had returned to regular work at his factory and had no problems with the government.

In the past two weeks, some of the 20 factory and office workers who make up the April Fifth Forum staff have posted on Peking's so-called Democracy Wall, the city's main wall poster area, unauthorized transcripts of the Wei Jingsheng trial, giving for the first time a full airing of Wei's defense against charges of passing military information to a foreigner and making counterrevolutionary statements. "Before the trial, we were very careful in our writing about the case but after the trial we had a clear understanding that Wei's problem was only an ideological problem and he should not have been arrested," said Xu, who is the oldest member of the staff and one of the three top editors.

"A few of our leaders are incapable of leading the people to attain a higher living standard, so they try to restrain the people. . . Yet it is precisely the people's never-ending demand for a better life that propels the society forward," Xu said. "The socialist system has many good points, but we must realize that the system has not yet reached the stage of perfection."

Xu and the rest of the staff, aged 22 to 36, print abut 1,000 copies of the 50- to 60-page monthly on an old, wooden frame mimeograph machine that requires each page to be printed with a hand ink roller. Xu bought the machine for the equivalent of $3.30 after getting a letter of permission from his unit's workers. He says they tolerate his after-hours activities because he has a good record.

The magazine is printed in one of the two 12-foot by 12-foot dormitory rooms assigned to Xu, his wife and his 7-year old daughter. The room is full of stacked paper. Photos of the late Chairman Mao, a source of controversy within the magazine, the late premier Chou En-lai and Xu's daughter are displayed on the wall along with magazine distribution charts. "Quite a number of people are willing to work for us, but if we have too many people there is not enough room for them to sit down," Xu said. The paper is produced by a small staff in a series of frantic late-night sessions each month.

Some of the staff are Communist Party or Youth League members. They sometimes split a few dollars in profits among themselves, but the magazine sells for only about 33 U.S. cents a copy, and almost all the revenue is eaten up by paper and mailing costs. There are about 200 mail subscribers. The remaining copies are usually sold with other unoffical magazines near the Democracy Wall wallposter area.

A recent issue listed about 15 other active unofficial publications that sell for about the same price. Some of them, including the April Fifth Forum, have asked for official government registration and offered to pay taxes on their revenues, but the offer has been ignored.

Xu agrees that much of the outpouring of unofficial publications reflects pent-up desires of many young Chinese to become writers, despite their failure to win one of the very few university places here. Xu's desire goes back to an essay he wrote as a middle school graduate in 1963. "I Demand Self-Study," was the title, and it voiced his wish to study social science on his own despite family demands that he get a job or try to go to college. Soon after, he joined the Army, working as a mechanic, then went to work at the Railway Bureau. His father had been an intellectual, a doctor killed in a motorcar accident when Xu was 8.

Xu admits he is more moderate in his views than his younger colleagues. On the subject of Mao, who had the dissenters of his age sent off to labor camps, Xu said, "He made mistakes in his later years but he is still a great revolutionary." The majority of the magazine's staffers, however, have "a lot of discontent about Chairman Mao," Xu said. "They cannot forgive him for his mistakes."

He is critical of young Chinese dissidents -- he prefers to call them members of the democracy movement -- who "do not quite understand the theory and some of the concepts of human rights." He said that "personally, I believe it is impossible to enjoy absolute freedom of speech."

Nevertheless, during the 1976 riots that led to his magazine's name, Xu was there demonstrating against the too rigorous application of Mao's ideas on austerity and expression. He wants to leave his $30-a month job to devote full time to the magazine. He is taking sick leave for what he calls heart trouble. Despite the previous history of government critics eventually being penalized for their work, Xu thinks he has a long career ahead of him.

"Privately run newspapers," he said, "can make the political life of our society more complete, and reflect the people's will from all angles."