Former Washington envoy Li Zhaoxing has been confirmed as minister of foreign affairs, ending months of speculation over who would succeed Tang Jiaxuan.
Mr Tang has been promoted to state councillor.
Mr Li, the vice-foreign minister, had been seen as a front-runner for foreign minister because of his expertise in dealing with the US, first as Chinese ambassador to the United Nations and later as ambassador to Washington.
His appointment reflects the importance the government places on managing relations with the US.
Mr Li, 62, is known for his pugnacious style - uncommon for a diplomat - in confronting China's critics.
During his tenure as ambassador to Washington from 1998 to 2001, Sino-US relations went through a turbulent period. Then president Bill Clinton's visit to China put bilateral ties back on track, but allegations of Chinese espionage, human rights abuses and illegal political contributions periodically threatened to derail the relationship.