Centuries ago, a great-great-great-grandfather of S. Van Lung, host, activist and one of Washington's best known businessmen, blatantly selected a family name that meant dragon, the moniker of the emperor. That was daring.

In more recent times, Lung's father, Lung Yun, a famous warlord, ended up a national hero, despite swinging between Chiang Kai-shek and Chairman Mao, and criticizing both. That was unheard of.

Their descentdant, Lung, has taken a similar, yet modified, approach to his beliefs. Through his ownership of the Yenching Palace restaurants, the well-known one on Connecticut Avenue and another in Alexandria, Lung has been an informal but visible and somewhat controversial character in the pro-Peking movement. He introduced Henry Kissinger to the intricacies of mainland cuisine before his historic trip, then fed the People's Republic of China liasion twice a day until they found a home.

Several years ago, because of his outspoken pro-Peking views, one of his restaurants was boycotted by the local Taiwan nationalist sympathizers. "personal threats," repeats Lung, his initial nervous laugh evaporating into a fixed frown. "I guess I shouldn't laugh, yes, the boycotters threatened to bomb me. I take it lightly and maybe that's foolish. But I believe that eventually the pro-nationalist forces will have a change of heart."

Since he arrived here as a student in 1945. Lung has bridged his Occidental and Oriental worlds and tried to reconcile them in various ways. His most recent venture is bringing "Lia Tse-hsu," a film about the British-Chinese War of 1839-42 to this country. The film has been suppressed during the Cultural Revolution because its approach is that of an entertaining lesson, not a revolutionary document.

"The story involves an important page of Chinese history," says Lung, 47, who negotiated directly with the Peking government for its release. His company, the Sino-American Export and Import Co. Inc., is distributing the movie in this country. "We thought there's so much misunderstanding about China, the policies and the people, this would be a small correction."

Lung pauses. Dressed in a collegiate beige crew-neck sweater, with a blue-plaid shirt collar peeking out, he orders lunch in his Connecticut Avenue restaurant. Dumplings for his guests, oatmeal with milk and two slices of toast for himself. For the second course, he switches to a Chinese dish of chicken and shrimp.

Probably because the West clings to the Eastern images of intrigue and romance, rumors abound about Lung: that he's a double agent, that he's an opium dealer, that he's a fantastic lover, that he was a liasion between the United States and Vietnam in the 1960s.

"You hear these things, like you are a spy, and you can sense that your friends might tease you but behind the teasing, there's some wishful thinking. I don't get annoyed. I just joke with my WASP friends that they don't need to be sending missionaries abroad but they need some here to teach about ethnic groups," says Lung.

Yet, his ruddy complexion darkens further when he is asked for details about his involvement with the historic trips of Kissinger and Richard Nixon to China. "It's flattering, and my role, that's for others to say. As an ordinary citizen I do have a small role to play, like the good Americans who go to China and explain what the average American thinks," says Lung. Then he ponders his role. "I should be described as a minor, small, American citizen who does have a dual cultural background and has strong feelings about both sides."

Lung, one of eight children, grew up in Yunnan province, the semitropical section that borders on Vietnam and Thailand. Since his father, Lung Yun was the governor-general of Yunnan and later, the vice-commander-in-chief of the Chinese Army under Chiang Kai-shek, life was privileged. When Mao came to power in 1949, Lung Yun was elected to a high post but didn't hesitate to criticize Mao's policies during the "Hundred Flowers" period in 1957. He was downgraded, but upon his death Mao had him buried in the historic Cemetery of the Revolutionary Martyrs.

In 1945 S. Van Lung was sent to the United States to study political science at the University of South Carolina and the University of Wisconsin. "Then I learned that political science and international relations don't make bread," he explains. In 1952, he opened a gift shop in New York. "It was reasonably smooth and sustaining." Next he invested in a Washington restaurant but says there was a dispute, so he moved here to recoup his losses and open a rival restaurant.

Now he has two restaurants, overseeing 90 employees he considers a family. Jane Shaw, widow of his original partner, says of Lung. "He's a blend of the old tradition and the new. After my husband died, he came to the house every day, preparing dinner, sitting down with the children. He's also very New World, sociable, outgoing and opinionated."

Yet the social role is one he downplays. At the Yenching Palace, he has been the host to congressmen en route to China, to the delegation that brought the pandas to the National Zoo, and to acrobats, PingPong teams, scientists, filmmakers, as well as names like Mick Jagger. "I do host a lot of people. Entertaining is alien to my nature. Because I come from a culture where simplicity is stressed, I do have a very simple life."

In 1971, after a 26-year absence, Lung returned to China. He wanted to see his father's grave, but his official escorts kept delaying his trip. When he finally arrived at the cemetery, he noticed his father's grave had a new tombstone. (This story is furnished by a friend. Lung is reluctant to elaborate or to discuss who he has met with on his eight trips to Peking since 1971.)

"I don't like to decorate my conversations with stories that make me look good or glamorous," says Lung. "The Americans might think those stories are interesting, just a fact of life. But the Chinese might think I am bragging, using the past for some benefit now," says Lung.

The Chinese have a phrase for that show of calculated modesty: K'e ch'i hua , or "polite talk."