Qiao Guanhua, 70, who as mainland China's foreign minister from 1974 to 1976 helped launch a new era in Sino-American relations, and who gained a reputation as one of his country's most effective diplomats before disapearing during the fall of the "Gang of Four," died of cancer here yesterday.

Perhaps his most significant role was as the man who sat through a night in 1972 with Henry Kissinger drawing up the Shanghai communique that led to a new stage in Sino-U.S. relations. In 1969, Qiao lead a team of Chinese officials in talks with the Soviet Union in an attempt to defuse an ugly series of armed clashes along the Sino-Soviet border. During the early 1970s, he headed China's first representation to the United Nations following its admittance to the world organization.

Criticized and ridiculed by Red Guards at the start of China's chaotic Cultural Revolution in 1966, Qiao nevertheless took over the Foreign Ministry in 1974. With the downfall of Mao's wife, Jiang Qing, in 1976 and the rise of pragmatic statesman Deng Xiaoping, Qiao was quietly replaced by Huang Hua.

No reason was ever given for his removal, but Chinese officials said privately that he had been under serious criticism for alleged connections with the purged "Gang of Four." Qiao reappeared in public last year, and last February was given a minor foreign affairs post as adviser to the People's Association for Friendship with Foreign Countries, which he held until his death.

Qiao will be remembered in international circles as one of Peking's most polished diplomats. He was a tall, urbane and well-dressed figure whose cheerful presence at diplomatic gatherings in Peking contrasted starkly with most other high-ranking Chinese officials. An accomplished linguist, Qiao was fluent in English and German and also spoke French, Japanese and Russian.

He was born in Jiangxi Province in southeast China. He received a degree in philosophy at Qinghua University in Peking in 1933. He then received a doctorate in philosophy at the University of Tubingen in Germany, making him one of the few Chinese communist officials to hold a doctorate and also one of the few educated in Germany.

Qiao was a leading journalist and propagandist during the 1930s and 1940s, and served in the foreign ministry after the 1949 communist revolution. Over the years, he became generally identified with the moderates led by former Premier Zhou Enlai and was a chief exponent of the premier's foreign policy, which sought increased contacts with the Western World.