Bei Dao, China's best-known writer, tried to go home and visit his family last week. Instead he was held at the Beijing airport for 12 hours, interrogated, asked to confess, told to repent and finally deported.

"They wanted me to kneel on the floor to the government, to betray the dissidents and to betray myself," the poet said yesterday from San Francisco. His only contact with his family was a glimpse of his brother through a window.

The incident, coming only a few months after the Clinton administration decided to separate human rights issues from its trade stance toward China, reflects a continued tendency of the Beijing regime to use the tools of repression against dissidents.

"They're sitting on a powder keg that's going to explode, and so they fear any form of protest," said Merle Goldman, author of "China's Intellectuals: Advise and Dissent." "The role of the poet as a leader and protester is a very traditional one in China, and that's one of the reasons they were afraid to let Bei Dao back in."

In exile since the Tiananmen Square uprising five years ago -- he's been teaching at the University of Michigan -- the poet said his only desire was to see his parents and daughter. The fact that his passport had been renewed early this year, coupled with Chinese assertions of increased tolerance, had given him hope. His visit, he said, was to be resolutely nonpolitical.

That didn't matter. After his name was entered into the computer at passport control in Beijing, the 45-year-old writer said, he was pulled aside and made to wait for four hours. Then a half-dozen Security Branch officials arrived. They set up a video camera in a small room, turned it on and started asking questions.

Why had he written an open letter in early 1989 urging the release of political prisoners? What was his connection with Human Rights in China, a New York organization of which he is a board member? What did he know about the activities of various exiled dissidents? Had he been secretly agitating against the government?

"I never do secret things," replied the poet, who has a worldwide reputation and is frequently declared an eventual bet for the Nobel Prize. "Everything I do is done openly. In the last five years I haven't been involved in organized political protest. I talk in interviews about my difference of opinions with the government, but I don't think this is organized political activity."

According to the poet, the response was: "You have a very bad attitude." At 9 a.m. last Friday, a dozen officials put him on a plane to San Francisco. A spokesman at the Chinese Embassy here said there would be no comment about the case.

Born in the same year as the revolution, 1949, Bei Dao has long been a symbol of dissatisfaction with it. In contemporary Chinese culture, the poet holds a position akin to that of Bob Dylan in this country during the '60s: Though he is not overtly political himself, his work is a source of inspiration for those who are.

At a New York conference sponsored by the writers' group PEN after Tiananmen, 21-year-old Wuer Kaixi, the most visible of the student rebels, was asked, "Where do you get your political ideas?"

"I got them from reading the poetry of Bei Dao," he answered.

The poem "The Answer" has become a particular anthem. One key verse says:

Let me tell you, world,

I -- do -- not -- believe!

If a thousand challengers lie beneath your feet,

Count me as number thousand and one.

The action against Bei Dao comes in the shadow of President Clinton's extension of China's most-favored-nation trade status in May. At the time, the president said he was convinced the Chinese would improve their human rights record if the issue were separated from that of trade sanctions. U.S. exports to China already total $8 billion a year, and both the business community and the administration's economic advisers have been eager to see that number grow.

China experts said yesterday that the president's expectations of a freer attitude had proven illusory.

"Frankly, ever since the most-favored-nation status was decoupled from human rights, there has been a crackdown on dissidents," said Goldman, a professor of Chinese history at Boston University. "Obviously the threat had restrained them. Now there's no meaningful pressure."

Jonathan Spence, professor of Chinese history at Yale, said the refusal to admit Bei Dao was "significant in that it shows there's a major lack of tolerance. The Chinese government fears intellectuals still, and knows it hasn't cowed all of them... .

"The attempt at the airport to make him confess is the sort of thing they did during the Maoist Cultural Revolution. All he had to do was say, 'I'm really sorry, I know I've vilified the Great Motherland,' and they would have said, 'Fine, come on in.' "

Spence linked the episode to other recent incidents, including the barring of disabled discus thrower Fang Zheng from an international competition in Beijing this summer. That happened after officials discovered that the athlete had lost his legs when they were crushed by a tank in the Tiananmen massacre. There's also the case of leading political dissident Wei Jingsheng, who was imprisoned for 14 1/2 years. After finally being released last fall, he was arrested again in April.

"These cases are a real indictment of this particular regime, and not very encouraging for those who believe in across-the-board human rights," Spence said. Siobhan Dowd, an official with PEN, added, "Of all the countries for which we keep records of writers in prison, China is currently the worst offender."

Bei Dao noted that the Chinese refusal to permit dissent was only going to make it increase.

"They need a free press so people can have a dialogue with the government and release this tension," the poet said. "Otherwise, it explodes. That's the way revolutions happen."