Deng achieves some of his leadership rejuvenation . . . but avoids upsetting the Army

China's new organs of leadership reflect the desire of Deng Xiaoping and his associates to achieve rejuvenation and ensure an orderly succession - while keeping the politically powerful armed forces under control.

The 12th Party Congress and its newly elected Central Committee have confirmed Mr. Deng in his substantive positions as chairman of the party's Military Commission and member of the Politburo Standing Committee. He is also certain to occupy a new concurrent position - chairman of the 172-man Central Advisory Commission.

Mr. Deng's proteges Hu Yaobang, Zhao Ziyang, and Wan Li are respectively general secretary of the party, premier, and vice-premier. The first two are members of the Politburo Standing Committee, while Wan Li, a member of the party Secretariat, has also been elevated to the Politburo.

Former Party Chairman and Premier Hua Guofeng remains on the 210- man Central Committee but no longer sits on the Politburo or its Standing Committee. Sixty percent of the Central Committee (including its 138 alternates) are new. According to Zhu Muzhi, spokesman of the Party Congress, 16 are over 70 years of age. The youngest member is only 38.

So much for rejuvenation.

At the top level, however, the Politburo Standing Committee has retained all its old leaders, including Marshal Ye Jianying. (Marshal Ye is in his 80s; Hua Guofeng, who was sacked, is in his early 60s.) The full Politburo consists of 25 full members and three alternates. Nine members, including two alternates, are new. But only three of them are under 70 years of age.

Some analysts interpret these results of Central Committee elections held Sept. 12 as a setback for Mr. Deng. The original plan, they believe, was for Mr. Deng to take most of his elderly colleagues with him into the Central Advisory Commission.

Others maintain, however, that Mr. Deng and his associates could not ignore the reality that the armed forces, loyal to Mao Tse-tung's memory and suspicious of many of Deng's economic reforms, remain a powerful political force. Mr. Deng himself, who has been both chief of staff and political commissar, possesses sufficient prestige to control the armed forces as chairman of the party's Military Commission.

But his associates do not, and one of the imperatives of assuring an orderly succession is to make sure that when the time comes for Mr. Deng to retire from active leadership, the armed forces will support the new leadership.

The armed forces have already begun a modernization program featuring better weapons and professionally trained commanders in contrast to the guerrilla style of the Mao days. But it will take many years for this program to come to full fruition.

For the time being, Mr. Deng needs concrete evidence that the Army's most respected and senior leaders - as exemplified by octogenarian marshals Ye Jianying, Xu Xiangqian, and Nie Rongzhen - are behind him, or at least not actively opposed. Hence Marshal Ye still sits on the Politburo Standing Committee and Marshals Xu and Nie on the full Politburo.

The actual day-to-day work of the Military Commission that runs the armed forces is in the hands of a Deng supporter, Yang Shangkun. The fate of the defense minister, Geng Biao, is unclear. He has lost his Politburo seat and his Central Committee membership and sits only on the Central Advisory Commission. It remains to be seen whether he will resign as defense minister and, if so, who will succeed him.

Another younger Politburo member, Peng Chong, who is in his 60s, has lost his seat on the Politburo and the Secretariat. He remains on the Central Committee and it is possible he may be given a regional assignment.

In day-to-day terms, the locus of power within the Central Committee must be the Secretariat, headed by Hu Yaobang as general secretary. Here dramatic changes have taken place.

Five Secretariat members have been given new assignments or sacked and six new ones (including two alternates) appointed. Among the new members are Hu Qili , the former mayor of Tianjin, who is a close associate of Hu Yaobang and is still in his early 50s, as well as Mrs. Hao Jianxiu, minister of the textile industry, who is only 48. Other figures close to Mr. Hu on the Secretariat are the economist Deng Liqun and Qiao Shi, who heads the party's international liaison department.

Ten members of the old Politburo came from the armed forces, and 10 members of the new Politburo (though not the same 10) also come from the armed forces. This shows the care the Dengist leadership has taken to see that the military voice continues to carry weight within the party. Among the new Politburo alternates is Gen. Qin Jiwei, commander of the Peking garrison.