Scrumptious viewing on PBS

Around 500 BC Confucius said in his writings: ''Food is the force that binds a society together.'' In 1983, Sue Yung Li is saying the same thing on film. According to filmmaker Li, the favorite pastime of the Chinese is eating. And the second most favorite pastime is talking about eating - before, during, and after the meal. Now - after her series ''A Taste of China'' - watching a television show about eating may have to be added to the list.

A Taste of China (PBS, premiered April 15, and continues for four Sundays through May 6, 10-11 p.m.; check local listings for premieres and repeats of episodes) is scheduled to coincide with President Reagan's trip to China. It is not, strictly speaking, a series about food, although food plays a great part in the series. Rather it is a series about China and the influences of geography and food supplies on its development. According to the series, the cultivation, preparation, and consumption of food are inextricably linked with Chinese art, philosophy, religion, and medicine. All these aspects are investigated with an expert eye and a skillful camera by Sue Yung Li, herself a native of China, now a resident of San Francisco.

But that is not to say that Chinese-food enthusiasts will not find food to start the taste buds quivering. Designer-filmmaker Li explores the daily life of ordinary people in China and makes it seem as exotic as a visit to the court of an ancient emperor. In the series she visits the northern plains of Ahandong, east of Peking; the mountain basins of Sichuan to the west; and the water country formed by the Yangtze River to the south.

The premiere concentrated on ''Masters of the Wok'' and the actual preparation of food by some of China's top chefs. The second show, ''Food for the Body and Spirit,'' traces the impact of religions - Taoism and Buddhism - on China and its cooking. The third program, ''The Family Table,'' examines the changes in the Chinese family through the routine of meals, focusing on the lives of a rural and an urban family. And the final program, ''Water Farmers,'' pinpoints the effect of geographical environment on cuisine, especially in the Yangtze Delta area, where everything is harvested in shallow canals.

There is a saying in China, according to the series narration, that food stirs the imagination of thinkers, sharpens the wits of scholars, and embellishes the spirit of the people. In ''A Taste of China,'' it will also educate and entertain the television audiences.

A chat with Sue Yung Li

When Sue Yung Li first arrived in the United States in 1949, after the communist ''liberation'' of her homeland, she was sent to a summer camp in Maine to learn the English language and American customs.

''Food was my biggest adjustment problem,'' she says with a laugh in a New York interview. She has arrived from her home in San Francisco to talk about her series, the second China series she has done for PBS. The first, ''Cities In China,'' was aired in 1979. Although she is a delicate, tiny woman with a traditional moonlike Chinese face, she is hardly dressed traditionally. She wears American blue jeans and has almost no trace of an accent.

''Even though they served potatoes - it was Maine, remember - at practically every meal, I was losing weight . . . .

''One day I came to dinner and they served something I couldn't recognize. When I didn't finish the serving, the cook came out of the kitchen and asked me if I liked it. I told him it was good, but I said, 'What is it?'

'' 'I made it especially for you,' he said sadly. 'It's chop suey!'

Why did she choose to focus on food in this series?

''Since I grew up in China during the Japanese invasion I got to see a lot of the interior of China, where life was really on the marginal survival level. The tradition was that you never leave a grain of rice in the bowl, because you must think of the farmers and how they must toil to produce the rice, as well as the many children in China who have no rice at all. . . . I guess that's why I have this feeling for the food connection.

''A Taste of China'' is scrumptious viewing for Chinese food fanciers and China-watchers alike.