The Chinese Communist Party has replaced its propaganda chief, Deng Lixun, a controversial orthodox Marxist accused by many Chinese writers and artists of pushing to excess a 1983 campaign against western ideas and influences.

A Foreign Ministry announcement issued today in response to a query from The Associated Press cited age as the reason for Deng's removal and said that most other party Central Committee department heads over the age of 60 would be replaced soon as part of the current campaign to promote younger officials.

Deng, no relation to China's paramount leader, Deng Xiaoping, is 70. The announcement said he was replaced by Zhu Houze, 54, former party secretary in the southwestern province of Guizhou.

The announcement said that as one of nine members of the Central Committee's Secretariat, Deng Lixun would remain in overall charge of propaganda work. His replacement as head of the propaganda department removed him from day-to-day direction of propaganda.

As one of China's leading "leftists," Deng Lixun and his statements are widely discussed among Chinese intellectuals and foreigners in Peking. His ups and downs are taken as signs of the relative openness or restrictiveness of the press and the arts in China.

Deng Lixun is an old associate of Deng Xiaoping, but some diplomats say that he is regarded as having given bad advice to the Chinese leader at the outset of a short-lived campaign against "spiritual pollution," or "decadent" western influences, in late 1983. The campaign, originally designed to curb harmful influences such as pornography, quickly widened to include condemnations of western-style clothing and cosmetics, long hair, western books and popular music. The drive created such concern that some Chinese leaders apparently began to fear that the campaign could damage the country's economic modernization plans.

In the spring of 1984, Deng Lixun was widely reported to have been ousted as a result of the campaign's excesses. But he soon reappeared in public, arguing for the need to promote communist ideology.

Because of the secrecy of the Communist Party's internal decision making, it is not unusual for the ouster of a key official to be surrounded initially by conflicting signals and reports. Few observers were ready at this stage to write Deng Lixun off completely. But some thought that his removal from day-to-day responsibility for propaganda meant that he was being eased gently toward full retirement, perhaps at a special party conference in September, when many younger cadres are to be promoted.

Some said they saw a hint of Deng Lixun's possible demise in an interview with party General Secretary Hu Yaobang published by a Hong Kong magazine last month. Hu praised Deng Lixun's talent and his behavior during the 1966-76 Cultural Revolution but also indicated that he was weak in the field of economics.

A participant in a Chinese writers' association conference last December that promised greater freedom for writers and artists said that when a message of regards from the absent and ostensibly ailing Deng Lixun was read to the conference, it was greeted with silence. Then at least a few delegates pounded the floor with their feet as a sign of protest against Deng Lixun, the participant said.