China appears to be at the edge of a momentous change that may be as significant as any since the Communist takeover 29 years ago.

What is happening, in effect, is that China is emerging from a near civil war, shaking off the results of a regime that in any Western nation would have been labelled Fascist, put together a shaky but workable coalition of leadership, and resolved to make up for lost time - roughly the 10 years of violence and severe refrogression that gripped China from 1966 to 1976.

This is the impression one gets from deliberate and chance interviews with dozens of experts and non-experts - Chinese and non-Chinese - before, during and after a three-week tour of the People's Republic as a member of an official delegation of American newspaper editors.

What the Chinese have in mind for this essentially primitive country of 900 million persons is to modernize between now and the year 2000. And to take the risks this entails - greater contact with capitalist countries and the creation of greater expectations at home.

Whether the present leadership can achieve what it intends is anyone's guess, including the leadership. Whether the forces being unleashed to reach these ends will be containable is likewise anyone's guess.

But what is not a guess is the smell of a Czechoslovakian spring in the Chinese air these days:

Item - During a drive down Peking's hugely, wide main street, an American diplomat points to a woman in a light blue blouse. He matter-of-factly says that color was not allowed last year, it's not drab enough. The same diplomat is stunned and flabbergasted to see water skiers on the lake at the summer palace. It's a first in Peking - and maybe in all China.

Item - Barberships in Shanghai are overcrowded - standing room only - with women waiting to have permanents. "Perms" seem to be the rage in this most stylish and cosmopolitan of all Chinese cities. Mustaches are beginning to sprout again on daring young men. Both hirsute effects were unthinkable two years ago. So too was listening to a Beethoven symphony or seeing the Szechwan Opera Company perform a traditional comedy or reading Catch-22, and Huckleberry Finn, as students now are doing again at Peking University.

Item - At Chungking, a West German attending a National Day celebration of song and dance for the second year remarks: "This year's performance is more daring and sexier than anything I've seen in China. And less political. You should have been here last year; it was very political."

Item - Corduroy is showing up in the stores for the first time even though cotton is in short supply and rationed.

Item - In the faded elegance of the Sun Ya restaurant on Nanking Road - Shanghai's Connecticut Avenue - where there once was an American soda fountain ("No one used it so they took it out."), a 72-year-old Chinese gentleman at the next table asks in English: "If I can be of help, just ask."

He is a graduate of John Hopkins University and a retired banker; with Western banks in Shanghai before the communist takeover and then, after, with the People's Bank. His son and grandchildren live in California, where one of his granddaughters just earned a Ph.D. at Berkeley.

"If this were a few years ago, I couldn't talk to you, and you couldn't talk to me," he says. Now he can and does. But he refuses to give us his name or allow us to take his photograph. He, like many others, is uncertain that the past is past, forever, let alone for his remaining years.

To be sure, these are mere snippets of change.

But to begin to understand how profound they are to some China watchers and to many Chinese, one must grapple with the magnitude of China's lost decade.

It began innocently enough. The late Chairman Mao Tse-tung, fearful of a developing elitism, invented the Cultural Revolution to counteract it. That was in 1966. But what Mao activated was a latent virus of egalitarianism that went wild and resulted in murder, mayhem and anarchy. In its most virulent years, the revolution was spread by the young Red Guards and workers who beat and killed people, wrecked factories, and smashed national shrines and treasures.

So, what began as preventive medicine ended in ideological metastasis.

This deadly tumult was encouraged by the so-called "notorious Gang of Four." These were four highly placed Chinese leaders who tried to usurp power after the death of Mao and Premier Chou En-lai. The gang included Mao's wife, Chiang Ching. She, the other three "gang" members and their followers - from all accounts - were xenophobic and bitterly anti-intellectual. One non-Chinese resident of China calls the former actress Madame Mao an "arrogant ignoramus."

Singled out for persecution, among others, were scholars, students and scientists. All scientific basic research, for example, came to a halt. So, too, did most higher education. Libraries closed. Universities shut down. Industrial and agricultural production fell precipitously. Artists were intimidated. One Chinese wistfully put it this way: "Worse than being beaten is a scholar unable to do his life work."

Consequently, progress eked out painfully and a great cost in the 1950s and early 1960s stopped. China came to a standstill. Worse, it began to slide into medievalism. Now it is groping forward again, maybe, in Chinese terms, even rushing forward.

Someone who has watched China for a long time and knows the old China and the new China well, but will not let his name be used, put it this way:

"Since the liberation [1949] there have been two main attitudes. The first is how much of the old should he preserved. The other has been how far and how fast to go in introducing new concepts.

"This argument has persisted right up to now. There continue to be struggles over it in the Chinese Communist Party and among the people. The Cultural Revolution was a more violent form of this argument.

"What this crowd [the present leadership] is trying to do is to restore sensible aspects of party policy distorted or ruined in the later stages of the Cultural Revolution. Of course, they want to steer it on a socialist course, rather than on a bourgeois course."