When it comes to freedom of speech, China is a pretty confusing place these days. Some Chinese are reluctant to say much, particularly to a foreigner, fearing that anything they say could get them into trouble. Others speak their minds with astonishing candor.

Students were vocal in anti-Japanese demonstrations a few months ago, and despite official efforts to bar repetition of earlier demonstrations, 200 to 300 students staged another march near Tiananmen Square here Sunday to protest nuclear weapons testing in China's northwest.

Writers and playwrights are also making statements through their works that might have landed them in jail just a few years ago.

The Communist Party has limited political freedoms and the freedom of speech since the 1940s. The crackdown on activists in 1979 and 1980 is still too recent to be forgotten. But some foreigners who have visited China repeatedly in recent years find the atmosphere freer now, within certain limits, than it has been in many years.

Evidence for this, they say, is not in politics or official statements, but in the conversation of ordinary Chinese and in the arts, particularly theater and films.

The degree to which the atmosphere is relaxed or tense for ordinary people seems to vary from region to region. But, as a rule, the greater the distance from Peking, the greater the sense of freedom. In the south of the country, in particular, one can find Chinese who volunteer unorthodox comments to a foreigner even on a first meeting.

In Guangzhou, formerly Canton, a taxi driver said he refused to go to a major propaganda movie being promoted by the Communist Party entitled "Song of the Chinese Revolution." He said that to buy a ticket would be "a waste of money." Guangzhou may be the least ideological place in China at the moment.

The people in Peking are supposed to be the most reserved in China. Bureaucrats, party cadres and a police force devoted in part to surveillance dominate the capital. But even here you can find Chinese who say amazing things if you stop to listen. A Chinese university student told guests at a dinner not long ago that most of the sons and daughters of high-ranking government officials she knew were lazy, spoiled and uninteresting. Her girlfriends, she said, were more interested in their boyfriends' ability to make money than in anything else. She portrayed a society far different from the one described in official propaganda.

Foreigners have less difficulty meeting and talking with Chinese people today than was the case three years ago. But when a Chinese takes the initiative to approach a foreigner, it's often a matter of seeking a favor. Some Chinese are convinced that an American who works for an important company or organization, will be able to get a son or daughter the sponsorship needed to enter an American university or find them jobs. That is the way the Chinese system of influence works, so the Chinese project it onto their foreign friends.

Over the past few months, this reporter has been approached by one Chinese seeking university sponsorship for a relative, another seeking a job for his son, and yet another seeking relief from oppressive officials in his home province through newspaper publicity.

A Chinese working in the Academy of Natural Sciences here carried his own six-point peace plan in the form of a letter to President Reagan and Soviet leader Mikhail Gorbachev to the reporter's office.

Those who are perhaps most interested in speaking their minds here -- artists and writers and students -- are subject to conflicting pressures that apparently reflect differing views among Communist Party officials.

A television program about the struggles of a young Chinese journalist shown early this year and again in the fall seemed to say that journalists should be encouraged to expose corruption. But the famous Chinese writer Liu Binyan of the party newspaper People's Daily has apparently been criticized for being too negative in his exposes. Some observers think that Liu was not clearing enough of what he wrote with the right officials. He seems to have stopped writing for the newspaper and is said to be working on a book.

Despite what looks like a cultural chill in several areas, some Chinese writers and artists continue to act as though they enjoy considerable freedom. Some insist that they have never felt more free.

After a Peking theater announced the closure last month of a controversial play called "Wo Men" ("We" in English), the play's producer held a press conference and said the play had the backing of some Communist Party officials and might be staged again.

Apparently reflecting the views of other officials, Shanghai's official Liberation Daily criticized the play for projecting a cynical outlook on life. The play is empty of hope or ideals, the paper said.

Shattered by the Cultural Revolution of 1966-76, the seven young people portrayed in the play never manage to recover their idealism, even after they have moved well into the current period. It is one thing to criticize the effects of the officially condemned Cultural Revolution and another to criticize today's conditions.

"Wo Men" had barely been closed when along came the play "Rubik's Cube," which, like "Wo Men," is drawing crowds of mostly young people to a Peking theater. A series of sketches, "Rubik's Cube" repeatedly challenges those who would blindly submit to authority.

In one sketch, a man places a sign marked "detour" on a road. No one in the crowd that gathers has the courage to go down the road. A guard with a red armband then admonishes those who dare to even consider taking the road to be patient and do the safe thing.

In the end, the man who placed the sign announces that it was merely a psychological test and that the road is safe to travel. The others urge him to go first, but he finds that fear has begun to affect him, too. He, too, begins to believe there is something wrong with the road and declines to use it.

Most Chinese do not go to the theater on a regular basis, and certainly not to this kind of theater. Most Chinese are more concerned with the prices of everything from clothing to electronic goods.

For escape from such everyday cares, Chinese are more likely to go to the movies or watch television. What they watch is often the simplest of entertainment, including martial arts films. These have little intellectual content, but they sometimes reveal popular attitudes.

Several months ago, the audience watching a film called "The Flying Thief of Emei" kept cheering the thief as he fought with the Chinese police. The thief fought them on rooftops, car tops and mountaintops before they finally subdued him.

Some Chinese apparently cheered the thief in the movie because they admired his skill in martial arts. Others apparently applauded him because they don't like the police. A university student said it was not so much a matter of disliking the police as a chance to sound off in a safe place, a darkened movie theater, against a symbol of government authority.

A foreign reporter went a second time to see the movie, at a different theater, just to make sure that the audience's reaction was the same. The crowd in the theater once again cheered the thief.

The reporter asked a Chinese interpreter on this occasion to follow one of the viewers out of the theater and get the viewer's comment on the film.

"People don't like the police very much," said the viewer, a man in his twenties, as he paused outside the theater.

"But," he said, looking over toward the foreign reporter, "don't tell the foreigner what I said."