A new constitution adopted this weekend by 800 delegates to an eight-day writers' conference in Peking marks a victory for Chinese leader Deng Xiaoping in a continuing struggle against opponents of his reforms, according to diplomatic analysts.

The analysts see the two groups jockeying to consolidate their position before a national meeting of party delegates in September to determine the future lineup within the Chinese Communist Party.

The struggle over reforms extends across several broad fronts -- economic, political and military as well as cultural -- and occasionally evidence of a dispute surfaces openly. An editorial that appeared last month in the official Peking People's Daily had to be corrected the next day, an apparent sign that supporters of Deng and Party Chairman Hu Yaobang had stirred opposition through their advocacy of moves away from rigid Marxist dogma.

But in some areas, Deng and his supporters have made gains recently. On the military front, for example, they recently forced 40 senior Army officers into retirement in keeping with Deng's aim to form a leaner, more technically modern military.

The New China News Agency reported that the new constitution of the China Writers' Association adopted over the weekend encourages Chinese intellectuals to "emancipate their minds and be bold to break new ground."

But the sensitivity of the document, which significantly departs from Maoist doctrine on art and literature, is hinted at by the official report, which says the constitution was approved only after "repeated discussions and revisions."

In a gesture that further strengthens Deng's victory, the conference also reelected the ailing veteran author, Ba Jin, 80, as its chairman.

Ba, author of the internationally famous novel "Family," was too ill to attend the meeting, but his retention as leader was viewed here as a political retort to a meeting last August of the Shanghai Federation of Literary and Art Circles. There, left-wing participants took over the senior positions and ousted Ba from the chair, replacing him with a leading leftist, Xia Zhengnong.

An opening speech to last week's congress by party official Hu Qili set the tone by saying that leftist tendencies were the biggest remaining shortcoming in the party's leadership of literature. Hu Qili is a close ally of Hu Yaobang.

The use of literary debates to issue political attacks is an entrenched Chinese political tradition stretching back through China's dynasties. Two of the bitterest political campaigns waged since the founding of the people's republic in 1949 have been launched under the guise of literary debate.

One was the so-called antirightist campaign in 1957, which silenced thousands of Chinese intellectuals who had responded to the party's call a year earlier to "Let a hundred flowers bloom, let a hundred schools of thought contend."

The second notable occasion was the Cultural Revolution, which lasted from 1966 to 1976 and cost millions of lives. Isolated by opponents of his economic policies, chairman Mao Tse-tung touched off the Cultural Revolution by commissioning an article attacking a historian and playwright, Wu Han, in November 1965.

The constitution endorsed on Saturday revives the "hundred flowers" theme and significantly reverses the Maoist contention that communist art and literature must be subordinated to the party and serve the workers, peasants and soldiers, set out as long ago as 1942 in Mao's "Talks at the Yenan Forum."

The new document is "more comprehensive and better suited to the new historical period than the old constitution, which limited the service to workers, peasants and soldiers," said Shu Peide, deputy secretary of the writers' congress.

However, a radio commentary on the congress over the weekend nevertheless reminded artists of their limits under Chinese socialism. "They absolutely must not just take creative freedom to mean, 'I can write whatever I think,' " the broadcast said.

China's top propaganda official, Deng Liqun, was noticeably absent from the week's meeting. In October 1983, he had launched an abortive attack on what he called the "spiritual pollution" introduced into Chinese society by Deng Xiaoping's economic reforms, opening China up to western influences.

Although Deng Liqun appears to have been thwarted in that round, analysts watching the Peking situation see leftist opponents of Deng Xiaoping as "powerful and influential."

Indicators cited as evidence that he has not yet consolidated his new policies include:

* The refusal of China's top economic planner, veteran leader Chen Yun, to endorse publicly the economic reforms;

* The failure of Deng Xiaoping to move his own supporters into two important posts in China's top ranks -- a seat in the party central political bureau and a seat in the party central secretariat. Both posts have been vacant for more than a year;

* Peng Zhen's claim on the next opening in China's innermost ruling circle, the Politburo's standing committee, when leading leftist Yeh Jianying dies. Peng is now chairman of the National People's Congress standing committee and is reported in some circles to be a fierce rival of Deng. A Japanese news agency reported over the weekend that Yeh is in a coma.

* Deng's failure to call a national party congress next September. Strong opposition to his reforms has left him ill-prepared to follow through on the public announcement of such a meeting, and the leadership has been forced to downgrade it to a national conference of delegates instead.

Diplomats warn that this opposition has strengthened, rather than subsided, since the Oct. 20 party meeting that endorsed Deng's urban and rural reforms.

"The news from Peking is always more favorable to Deng Xiaoping than from the provinces where there remains formidable resistance among stubborn leftists and disenfranchised cadres and bureaucrats for Deng's opponents in Peking to draw upon," one diplomat said.