China's Communist Party announced sweeping changes in its executive machinery today, including the resignations of 10 of the 24 Politburo members in what amounts to the biggest political shake-up of that powerful body in more than a decade.

The changes, announced after five days of secret meetings, involve the resignation or retirement of 131 senior party officials, according to the official New China News Agency. They are seen as paving the way for a transfer of power that has been evolving here from aging revolutionaries to a younger generation charged with promoting China's new open-door policies toward foreign trade and investment and economic reforms.

Although replacements for the 10 retiring Politburo members were not immediately announced, diplomats said the changes now in the making also clearly pointed to a substantial consolidation of power for Chinese leader Deng Xiaoping and of his efforts to promote reform.

Among the resigning members were six aging military men, including several considered to be less than enthusiastic supporters of Deng's reforms to decentralize the economy and open China to the West.

Most prominent among those retiring were 88-year-old Marshal Ye Jianying, who resigned from the six-member Politburo standing committee, the most powerful party body, and Politburo member Deng Yingchao, 81, China's highest ranking woman politician and the widow of former premier Chou En-lai. Ye is believed to have doubts about the economic reforms and has come to symbolize military conservatism for many Chinese. He has been seriously ill and inactive for the past few years.

The resignations were announced by the Chinese news agency, which cited letters to the party's Central Committee from 64 party cadres, including the 10 Politburo members, who the agency said "have requested to resign." The committee has 210 full members and 136 alternates; the resignations mean a change of about 18 percent in that body's overall membership.

Altogether, the agency announced the resignation or retirement of 131 members of the Politburo, Central Committee, Central Advisory Commission and Central Commission for Discipline Inspection.

In the Maoist era, major top-level shake-ups were marked by bitter infighting and purges. The biggest previous Politburo shake-up in 1973 constituted a purge of followers of the late defense minister and party vice chairman Lin Biao, who was the designated successor to the late chairman Mao Tse-tung.

But diplomats who specialize in Chinese politics said that Deng still must compromise on some appointments. Thus, in the end, while new appointments to the Politburo are likely to include a majority of reformers, they probably also will include individuals who have doubts about the reforms.

A Central Committee communique announced today that a special party conference will be held on Sept. 18 to appoint new members to the Central Committee, followed by another Central Committee meeting to name replacements for the resigning Politburo members.

Although the Politburo meets infrequently, it is still, according to the party's constitution, the country's highest policy-making body. By placing his supporters in the Politburo, Deng takes out an "insurance policy" against a possible future attempt to reverse his reform policies, one diplomat here said.

According to the Chinese news agency, military men resigning from the Politburo besides Ye Jianying include two other marshals, Nie Rongzhen, 86, and Xu Xiangqian, 83, as well as Li Desheng, 69, the recently retired commander of the strategic northeastern military region. Also resigning were Wei Guoqing, 79, former director of the armed forces' political department, and Zhang Tingfa, 67, former Air Force commander.

Of the 64 persons resigning from the Central Committee, at least 22 were senior military men, including former military region commanders as well as the current defense minister, Zhang Aiping, 77.

The military gained heavy representation in both the Politburo and Central Committee during the tumultuous Cultural Revolution from 1966 to 1976, when its intervention was required to restore order.

Some observers see the changes announced today not so much in terms of constraining the military as in bringing the Politburo more into line with the expertise required by the economic reforms.

"The Politburo was becoming anachronistic," said one diplomat. "A lot of Politburo members had no idea what it means to talk about wage and price reforms.