Capping nearly two weeks of meetings in which every top party organization was revamped, China's Communist Party today selected six new members of the ruling Politburo, five of them closely associated with the economic reforms introduced by the country's top leader, Deng Xiaoping.

In addition, the party named five reform-minded supporters of Deng to the 11-member Secretariat in charge of day-to-day policy-making.

The changes amounted to a nearly complete sweep of new party Politburo and Secretariat positions for the reformers. They give Deng and his senior colleagues a Politburo decidedly in their favor for the first time, and set the stage for the rise to the highest leadership positions of men now capable of serving until the end of this century.

Most prominent among newly selected politburo members were Hu Qili, 56, and Li Peng, 57, considered likely to take the positions of party general secretary and premier, respectively, when General Secretary Hu Yaobang and Premier Zhao Ziyang step down. Hu Qili, a scholarly looking advocate of China's market-oriented reforms and open-door policy toward foreign trade and investment, has been serving as permanent secretary of the Secretariat. Vice Premier Li Peng is a Soviet-trained electrical engineer and energy expert.

In 1987, at a party congress, a number of senior leaders, now in their seventies and early eighties, are expected to retire and turn over the highest positions to successors in their fifties and sixties. The new leaders, who were promoted to dozens of high-level party positions in recent days, are the first generation of Chinese Communist Party leaders to be mostly university trained professionals.

The selection today of new Politburo and Secretariat members reflected not only the influence of Deng Xiaoping but also that of his protege, party General Secretary Hu Yaobang. Of the six persons given new Politburo positions, three once held leading posts in the Communist Youth League, which was long headed by Hu Yaobang. Of the five named to the Secretariat, three had served in leading youth league positions.

Changes made over the past 12 days in the Politburo, Secretariat, Central Committee, Central Advisory Commission, and party Central Discipline Inspection Commission amounted to one of the largest transfers of power to take place in the history of any communist movement. Altogether, 131 senior party officials resigned or retired. The changes appeared to make it more likely that the economic reforms advocated by Deng Xiaoping will last.

In a speech last week, Hu Yaobang described the leadership change as "quite smooth," but speeches delivered at the end of a six-day special party conference indicated that there has been considerable disagreement over the scope and pace of Deng's reforms. Some diplomats say, furthermore, that the fact that Deng and his allies filled only six out of 10 Politburo vacancies opened up by retirements must have reflected disagreements over several potential replacements, who failed to make it to the Politburo.

Some diplomats also saw as a sign of disagreement the failure to find a replacement for Marshal Ye Jianying, who resigned from the six-member Politburo standing committee, the most powerful party body. But none of these party bodies have fixed numbers of members, and other diplomats saw little significance in the failure to find replacements for all the open positions.

Most evident to everyone was the reduced profile of the Chinese military in top party bodies. The old 24-member Politburo included nine aging military men. Of these, six retired. The newly constituted 20-member Politburo has only three military members: Yang Shangkun, deputy chairman of the party's military commission; Yang Dezhi, armed forces chief of staff, and Yu Qiuli, head of the People's Liberation Army general political department.

One of Deng Xiaoping's consistent aims in recent years has been to move the military out of politics. With the latest changes, he and his allies appear to have taken another major step in that direction.

But the reformists did not necessarily get their way in every respect. Based on their backgrounds and pronouncements, about half a dozen carry-overs among the 20 full members of the new Politburo can be considered less than enthusiastic reformers. Some observers describe them as fundamentalists or conservatives. They do not constitute an organized opposition, but they can slow things down.

And three out of the 11 Secretariat members are also seen as part of the "go-slow" tendency.

Against a background of growing problems associated with the reforms -- inflation, corruption, an overheated economy, and social problems and disparities -- Deng Xiaoping in his final speech to the special party conference yesterday made a nod in the direction of the go-slow constituency by delivering a fairly orthodox set of remarks about the need to tighten discipline and intensify the study of Marxism.

Statistics released here yesterday showed that the country's foreign trade deficit may reach a record $18 billion by the end of the year, which means imports running far beyond the level planned, a further drop in foreign exchange reserves, and more economic trouble.

According to a communique issued today, the Central Committee elected six new Politburo members. In addition to Hu Qili and Li Peng, three others have been closely associated with Deng Xiaoping and Hu Yaobang and the reforms: Vice Premier Tian Jiyun, 56, a financial expert; Qiao Shi, 61, former head of the party's organization department, and Wu Xueqian, 64, foreign minister and former associate of Hu Yaobang in the Communist Youth League's central committee.

The other new Politburo member is Yao Yilin, a party veteran and economic planner who was once closely associated with Chen Yun, the standing committee member considered the leading advocate of a cautious approach to reform.

The youngest official to gain a major promotion today was Wang Zhaoguo, a 44-year-old automotive engineer and head of the party Central Committee's general office, who has now been named to the Secretariat.

In one subtle shift in listings, the party indicated today that Hu Qili may be the fastest rising of the six new Politburo stars. The Central Committee communique placed Hu Qili immediately after Hu Yaobang when it listed the Secretariat members. Until recently, Hu Qili had always been placed much further down on the list of Secretariat members.