China announced today it plans to seek membership in the International Monetary Fund, the World Bank and other international financial institutions, pushing aside one of the last barriers to its full participation in world trade.

Vice Premier Gu Mu, speaking at a press conference here, also revealed a rapid climb in Chinese business abroad, including a 40 percent jump in exports and 70 percent jump in imports in the first half of this year.

Gu indicated, however, that Peking was bothered by potential difficulties in dislodging the rival nationalist government on Taiwan from membership in international bodies like the IMF. He said Chinese officials were still discussing the best timing for their applications to the world bodies.

Membership in the leading international lending bodies would greatly strengthen Chinese trade ties with the West, particularly the United States, and open up a huge amount of new capital in the form of low-interest loans to finance Peking's crucial modernization program.

Gu, summing up China's economic prospects as the Oct. 1, 30th anniversary of the People's Republic nears, prefaced his announcement on IMF membership with frank statement of the country's weaknesses. "Our economy has not developed fast enough, our economic structure is not rational . . . our science and technology are backward," he said.

Diplomats here estimate China has so far lined up about $20 billion in overseas lines of credit, including what Gu said were loans from "the United States, France, Italy, Canada, Sweden, Japan and other countries."