Jiang joined the CCP in 1946 and graduated from Shanghai Jiao Tong University the following year with a degree in electrical engineering. He worked in several factories as an engineer before receiving further technical training in the Soviet Union about 1955. He subsequently headed technological research institutes in various parts of China. In 1980 Jiang became vice minister of the state commission on imports and exports. Two years later he became vice minister of the electronics industry and from 1983 to 1985 was its minister. He had meanwhile become a member of the Central Committee of the CCP in 1982. Named mayor of Shanghai in 1985, he joined the Political Bureau (Politburo) in 1987.

The Chinese leadership was reshuffled following the forceful suppression of demonstrations in Beijing and elsewhere in 1989, with Jiang succeeding Zhao Ziyang as general secretary of the CCP. He was a compromise choice who combined a commitment to continued free-market economic reforms with a determination to preserve the CCP's monopoly on political power. Also in 1989 he succeeded Deng Xiaoping as chairman of the party's Central Military Commission. In 1993 he became president of China, elected by the National People's Congress.

With Deng's death in 1997, Jiang became paramount leader and consolidated his power. He began to reduce the state's ownership and control of some of China's 300,000 industries, beginning with a privatization plan in 1997. During the late 1990s Jiang attempted to improve the country's uneasy relationship with the United States. In 1997 he participated in the first U.S.-China summit in almost a decade, and at a follow-up meeting in 1998 he openly discussed his human rights record, which had been criticized by the West. In 2002 Jiang resigned as general secretary of the CCP and the following year stepped down as president after serving the maximum two five-year terms; Hu Jintao succeeded him in both positions. Jiang remained in charge of the Central Military Commission until stepping down in favour of Hu in September 2004.