BEIJING, NOV. 5 -- China's official press described Zhao Ziyang, the country's new Communist Party chief, today as a leader who has established the ideological basis for further economic reform.

A western diplomat said the praise for Zhao's ideological work is one more sign that he is being groomed to be the country's paramount leader.

One problem for reformist officials such as senior leader Deng Xiaoping, 83, and his protege Zhao, 68, has been the lack of an ideology to provide the basis for their experiments.

At the recently concluded 13th party congress, Zhao expanded his responsibilities to include the interpretation of party doctrine. The theory he put forward -- that China is in "the primary stage of socialism" and therefore needs to continue experimenting with market mechanisms -- is seen by some observers as filling the ideological vacuum.

Since Confucian times, Chinese leaders have attempted to legitimize their rule as the upholders of an all-embracing doctrine, whether it be Confucianism or communism.

Chinese publications are describing this latest development as a theoretical breakthrough. "This is a good design," Deng was quoted as saying earlier this year by the official New China News Agency.

According to a news agency report published in leading newspapers today, Zhao made the theory the basis for his report to the party congress. A 19-member drafting group helped prepare the report and Zhao presided over each draft, the news agency said.

While the idea of primary-stage socialism has been used in previous party documents to explain new practices, Zhao used it for the first time as the foundation for the development of the economy, the news agency said.

"The primary stage of China's socialism is one in which we shall gradually put an end to poverty and backwardness," Zhao said in his report. This period would last "at least a hundred years from the 1950s," he said.

In the 1950s, Mao Tse-tung declared China to be in an "advanced stage of socialism."

During the disastrous Cultural Revolution, launched in the 1960s, Mao drowned the country in ideology. But in the late 1970s, based on the motto "seek truth from facts," Deng emphasized economic results over ideology.

Some party theoreticians carried this emphasis further than Deng and some traditionalists would have liked.

Su Shaozhi, former director of the Institute of Marxism-Leninism and Mao Tse-tung Thought, is credited with having done much of the work to develop the theory of the primary stage of socialism. But Su offended party ideologues with his advocacy of wide-ranging political changes, such as western-style checks and balances. In August, Su, 63, was forced to retire as director of the institute. He retained his party membership.

One of Su's harshest critics was Deng Liqun, 72, the former party propaganda chief who was retired from the party's Central Committee following the recent congress.

Deng Liqun's fortunes are often viewed by Chinese intellectuals as a barometer of intellectual freedom at any given time. Deng, no relation to Deng Xiaoping, had been widely expected to gain a position on the ruling party Politburo during the recent congress.

But, one usually well-informed source said, Deng failed to obtain enough votes in a preliminary election to be elected to the full Central Committee, much less to the more elite Politburo.