Friendship no longer ranks ahead of winning for Chinese Olympians

''China has changed its emphasis in international sports competition,'' says the reporter from China Sports magazine. ''In the past, it was friendship first, competition second. Now friendship and competition go together,'' Chang Xiao Yan explains.

Ms. Chang is being diplomatic. Gone are the days when China would artfully let visiting athletes win contests in order to strengthen international friendship. This year's Olympic squad of 225 athletes and 49 coaches is determined to eradicate, once and for all, the past image of China as weak in sports.

What is more, hundreds of millions of fans here at home have been primed by the Chinese news media to cheer every victory and share every defeat as they watch their Olympic standard-bearers on television.

The media have also been persistently reminding the public that China's participation in the games is a historic event. Indeed it is. Only one athlete from Japanese-occupied China debuted at the 1932 Games, also held in Los Angeles. And only a handful participated in subsequent games - until, in the 1950s, China pulled out of the Olympic club altogether because of Taiwan's membership.

But these fledgling efforts won China no medals. ''Owing to her impoverishment and backwardness in sports (in those early years), she could neither send many athletes for participation nor achieve good results in competition at the games,'' wrote He Zhenliang, a Chinese member of the International Olympic Committee, in a recent issue of China Sports.

China rejoined the Olympic movement in 1979, after an acceptable formula was worked out which permitted both Taiwan and the mainland to participate. Then, ironically, the nation's reentry was delayed four years when China joined the boycott of the 1980 Moscow games because of the Soviet invasion of Afghanistan.

So this year there is a keen interest here in who will be the first to win an Olympic medal for the world's most populous nation - and, of course, much speculation about which athletes may take away gold. A number of the athletes warming up in Los Angeles are already among China's first sports superstars.

Perhaps the best known is high jumper Zhu Jianhua, who has broken the world record several times just this year. In a recent interview he said he was aiming at a gold medal - pitting himself against the United States star Dwight Stones - and wants to better his own record of 2.39 meters (about 7 feet, 81/10 inches) set last month in West Germany. Other well-known athletes include weightlifter Wu Shude (world record holder in his 56-kg [123-pound] class), women's basketball team captain Song Xiaobo, and gymnast Li Ning.

China expects to enter 17 Olympic events, and observers here rank a number of its teams as strong enough to compete for medals with the United States, Japan, and West Germany. Sportswriters for the official Communist Party newspaper, the People's Daily, are now saying that China has good prospects for medals in the high jump, women's volleyball and basketball, weightlifting, men's and women's gymnastics, women's diving, and archery. The list reflects China's demonstrated strengths in international competition during the past several years: Its most notable successes occurred at the 1982 Asian Games in New Delhi, where China took home 61 medals (against Japan's 57) and emerged as the leading sports power in Asia.

Like many of their colleagues from the Soviet-bloc nations, however, China's athletes are subsidized by the state. Weightlifter Wu Shude said in an interview recently that he receives a ''cash subsidy'' of 98 yuan ($49) per month and attends a special sports school. (This subsidy is slightly more than the average factory worker makes.) But the happenstance sort of way that many of China's top athletes got their start may be familiar to Western amateurs.

Wu, for instance, was spotted by a coach while playing in front of his school. He was then in ''middle school'' (high school) and said he had never seen a weightlifting competition. At that time, he says, he was very weak and thin. High jumper Zhu Jianhua was also discovered on the street by his coach, who noticed his big feet and long legs. When Zhu entered the ranks of China's world-class athletes, he insisted on keeping his original coach and friend, Hu Hongfei.

Officials here express concern about security at the games. They seem particularly intent on preventing such embarrassing defections as that of Hu Na a year ago, in which the leading Chinese women's tennis player was granted political asylum in the United States.

The Chinese Olympic Committee, however, has dismissed death threats against its athletes contained in a letter sent to a number of Asian countries participating in the games. The letter, purportedly written by the Ku Klux Klan in the United States, has ''all the hallmarks'' of a disinformation campaign - possibly by the Soviets - according to a US State Department spokesman.