One of the greatest forced population shifts in history - the movement of 14 million urban Chinese young people to the countryside for a minimum period of two years seems to be slowing down following the death of its instigator, Mao Tse-Tung.

The last few months the official Chinese press has carried relatively few reports about eager young people trudging off to farms as the school year ends. Instead the official media have appealed for improved training of "intellectuals and experts of all trades." This suggest that some talented high school graduates are being allowed to proceed directly to university study instead of being required to pitch manure for two years.

It is impossible to tell just how much Peking has softened the forced migration policy, which has created resentment among parents and forced some young people who could not adjust to farm life into petty crime.

But Japanese correspondents in Peking and American journalists passing through Canton have been told that some high school graduates are now skipping the program and that others have been assigned to farms not too distant from their city homes.

After the death of Communist Party Chairman Mao in September and the purge of his more dogmatic followers in October, the new administration of Chairman Hua Kuo-Feng at first virgorously defended the assignment of educated youth to the countryside. The New China News Agency featured a glowing account of Hua's approval of the transfer of his youngest daughter to a rural production brigade after her high school graduation in 1974.

But the article also noted that Pingku County, where Hua's daughter Hsiao Li was sent, was only "on the outskirts of Peking," within relatively easy reach of her parent. The distance was short enough, one article said, for party leaders of the brigade to visit the parents of all the young people assigned to the unit and report on their progress. Until this year the press had been full of praise for youths who moved to distant raw frontiers like Tibet or Sinkiang. There are fewer of such reports this year, and Japanese reporters in Peking say youths leaving school this spring are all promised posts no farther than 65 miles from the city, and may go home once a month.

The Chinese Communist Party came to power through the support of uneducated rural peasants, and has generally distrusted educated city folk. Official party journals have encouraged urban youth to get a taste of farm life, but in 1968, after young urban Red Guards got out of control, Mao made country living mandatory. "It is necessary for educated young people to go to the countryside to be re-educated by the poor and lower-middle peasants," he said.

There were other good reasons for the decision. Like cities of most underdeveloped countries. China's cities were overcrowded and its schools were turning out more educated young people that it had white-collar jobs to fill. For a few years after the 1968 decision, most of the nation' unversities were closed, then reopened with smaller classes of young people who had served the requisite two years on farms, or in some cases in factories or the army.

One analyst here calls the program "one of the most successful population control systems ever," and said he doubts that the Chinese plan to do much more than excuse a few of the most gifted science and language students from participating.

The Chinese have not said how many of the displaced youths have remained in the countryside after their two years were up, but population analysts say the growth of large cities like Peking and Shanghai has come to a halt in recent years.

But youths who try to sneak back into the cities have created a serious crime problem. Without jobs to provide them with ration cards and salary, they must steal or even become prostitutes. There is little indication that the new administration in Peking plans to do anything more than bring such young people to swift justice when they are caught.

But young people with particular academic talents may have a way out. In a front-page article entitled "The Proletariat Must Have Its Own Experts," the People's Daily this month gave an old Mao quote new luster: "To build socialism, the working class must have its own army of technics cadres and of professors, teachers, scientists, journalists, writers, artists and Marxist theorists. This must be a vas army. A small number of people will not suffice."

The need to meet Chairman Hua's goal of a modern industrial nation by the year 2000 requires rapid training of far more technicians than are now at work, the article and several others like it say. Excusing some youths from the program risks creating in China the sort of technical elite class that Peking argues is the worst feature of Soviet society. But the men now in charge of post-Mao China are bureaucrats who have become accustomed to privileges for the best-trained and most experienced, and they may have fewer qualms now about creating a younger generation in their own image.