China's post-Mao Communist Party appears to be decentralizing some controls in a major provincial reshuffle, with new governors handling free markets, birth control and free expression in very different ways.

In a series of provincial-level personnel changes disguised as new elections, most provincial party leaders have relinquished their jobs as governors, often to specialists in administrative and technical work. The moves have fueled renewed speculation that Chinese Communist Party Chairman Hua Guofeng might also relinquish his job as premier sometimes this year.

The changes appear to reflect the wish of a group of party veterans, led by Vice Premier Deng Xiaoping, to return to the system of the 1950s, when party committees set policy and somewhat separate government bodies executed policy in pragmatic, individual ways.

The official press has lately been emphasizing a favorite Deng slogan: "It does not matter whether the cat is black or white, just so it catches mice." Since the mid-1960s when Deng was temporarily purged for voicing such pragmatic sentiments, government and party power has often been held by one man in each province and policies appeared to follow more closely party dogma than they have in recent months.

Interviews with Chinese officials here and in some provinces indicate, however, that the party still ultimately controls all decisions. The several new provincial governors still attend party committee meetings where, as second and third secretaries, they are outranked by the local party chief and they must be careful how much they experiment in their jobs.

New variations in applying important national policies at the local level appear to arise both from the changes in local leadership and the willingness of the central government to wait for results before criticizing local initiative.

The government's vital campaign to reduce births and cut population growth to 0.5 percent by 1985 has been handled very differently from province to province.

In Sichuan, Shanxi and Anhui, local governments have announced rewards for those who limit their families to one child and penalties for those who have three children or more. Other provinces have neglected penalties and apparently tried simple persuasion.

One recent foreign traveler noted strict large family penalties posted in a Shanxi factory, while in Nanjing, part of Jiangxi Province, a huge poster merely recounted the prosperity enjoyed by Western countries that practiced birth control. It mentioned no strict penalties and rewards for Chinese parents n the city.

A recent play, "If I Were Real," was banned by Shanghai authorities. It sharply criticized city officials who granted favors to a young con man pretending to be the son of a powerful general.

In Peking, a television showing of the same play was canceled at the last minute. But in Canton, in guangdong Province, and in xian, in Shaanxi Province, the play has been advertised in the local official newspaper and in official posters.

Similar differences have been noticed by travelers in the numbers of free street markets allowed in different areas.

The reshuffle of provincial governments began this summer as people's congresses and people's governments replaced the revolutionary committees that had ruled local government since the late 1960s. The new system fixed more responsibility and accountability on a single governor, similar to the system followed in the 1950s and early 1960s.

In Anhui Province for instance, veteran party leader Wan Li, a close associate of Deng Xiaoping, relinquished his post as revolutionary committee chairman. Zhang Jingfu, former finance minister, was selected as the new governor for the province.

So far, only in the two largest cities, Peking and Shanghai, and in the large southern province of Guangdong does the party chief also hold the top government job. While in 20 provinces the governor and party chief are different, in six of those provinces, the party chiefs still serve as chairman of the standing committee of the people's congress, whose members are supposed to be directly elected by the population to give the government legitimacy and a representative assembly. In some troublesome provinces, such as Liaoning and Jilin, congresses have not yet been held and governors have not been selected.

Since Hua Guofeng 58, assumed both the jobs of premier and party chairman after the 1976 deaths of premier Chou En-lai and chairman Mao Tse-tung, recurrent reports have suggested he would eventually give up the premier's job.

Top government officials predicted in early 1978 that Deng would soon become premier. The National People's Congress that year failed to select Deng, however, and the 75-year-old vice premier told some visitors he did not want the job.

New rumors here suggest Zhao Ziyang, about 62, the party chief in Sichuan and a well-publicized Deng protege, may be candidate for the premier's post, or at least a replacement for Deng as senior vice premier if Deng retires. A recent announcment that the party chief in Qinghai province, Tan Qilong, has been transferred to be Zhao's second in command in Sichuah suggested Zhao might soon leave Sichuan for Peking.

The rumors also reported that Zhao has declined the premiership, and it is hard to imagine a leader as vigorous as Deng retiring, when the Chinese practice has been to stay in office until death.