I WAS A FOREIGN GUEST in China in 1978 and again in 1980. The Chinese were warier of me on the first visit than they were on the second. This is one personal and impressionistic measure of the change now taking place in that vast country.

Other indicators of change over so short a time period are readily evident, more in the cities than in the countryside. In 1978, pigs and vegetables plots were about all that was privately owned. Today, there are private cars and trucks, private markets, barbers, tailors and restaurants. One Chinese told me last year, "The private tailors are more expensive than the state store, but they do better-quality work."

In 1978, color was just returning to dress. It had been barred during the "terrible time" of the notorious Gang of Four. Today, on the main shopping street, around the corner from the Peking Hotel, is a window display of colorful, patterned lingerie. Unthinkable two years ago. There is also a Seiko watch store.

One more example. In 1978, the Chinese would not accept American Express checks. Today, at the Canton airport the foreign guest is greeted with a huge billboard advertising the American Express credit card and the word, in English, "Welcome."

Orville Schell, a chronicler of modern China, frets about these kinds of changes and the more profound implications that the intruduction of Western technology and its concomitant cultural baggage might have for the People's Republic of China. He puts it this way:

"When Deng's [Chinese leader Deng Xiaoping] lieutenants speak of their forumla for developing their country, 'The Four Modernizations' -- industry, agriculture, science and technology, and national defense -- it all sounds so simple: a neat, surgical procedure whereby the best features of the industrialized West will be introduced into China like an organ transplant. But is anyone calculating the likelihood of tissue rejection? The possibility that the spirit which comes with Western technology may wreak unintended havoc on Chinese society?"

For 178 pages Schell finds ways to ask the same question. And he does it cleverly by traveling between China, where he just manages to bump into the most articulate Chinese anyone has met there, and the United States, where he accompanies Deng and other Chinese leaders on their travels to Washington, Disneyland, Atlanta and Texas.

His chance encounters in China are certainly better than any I had (admittedly, he speaks the language and I don't). For example, there is Benefit-the-People Wang, a despicable pimp who hangs out in the Peace Cafe, a "joint" (my word, not his) which existed near the Peking Hotel but which has been closed down by the authorities. And there is Ling Mulan, an extraordinarily sensitive and articulate young woman:

"You've seen all the girls who have started to curl their hair up tight at the hair salons. But I don't think they really know what beauty is. They're just imitating. They have not had a chance to develop a sense of beauty. They think that if they can look like foreign models, they will be beautiful. Now there are some girls who have started wearing foreign hats.I think they're quite ugly and inappropriate. But I still don't think that our government should forbid to wear them.Instead, they should try to explain what beauty and good taste really are. They should help lead the opeople toward it."

In between, he sketches the history of previous attempt on the part of China's leaders to introduce Western technology and its consequences. Thus, for example, Schell tells us about the promotion of Western learning in the China of the late 19th century.

"It proved," says Schell, "much more difficult to integrate the dynamic and unruly world of Western technology into Chinese life and culture than the nineteenth-century reformers had supposed."

He notes, too that:

"It became increasingly obvious that foreign technology and foreign culture were inseparable, and that they comprised a form of domination far subtler but every bit as powerful as imperialism itself. It was not possible to separate the two and ship 'Western technology' off to China to work like an obedient team of borrowed horses. Technology was not a trained animal that would obey anyone's command and jump through hoops. It was more like a 'wild beast' (as the Chinese were fond of calling foreigners in the early days), which, at any minute, might leap out of its confinement and ravage its custodians."

This, then, is the thesis. Schell is wary lest the virus of Western technology run up China's arm, infect the body, and ravage the China he has come to know and love. Indeed, he is wistful about an "old China," the way many veterans are wistful about the "old Army."

If you are in the mood for a quick, brightly written, hard-bound booklet about a handful of interesting and probably atypical Chinese, and one chronicler's alarm, Schell provides it.

I, for one, think there is a more immediate and more profound challenge. This is whether Deng Xiaoping and his colleagues -- in their rush away from the ravages and stagnation of the Cultural Revolution -- have unleashed interal forces which they will be unable to control. To be sure, Western notions, influence, and education play a part. But rising expectations, renewed freedoms, picking at ideological scabs, and old lusts seem to be buffeting China more than Western technology and its cultural accouterments. These are the threats to China's stability that I would watch.