Ch’ŏngjin, city, northeastern North Korea, capital of North Hamgyŏng Province. It is an important ice-free port on the East Sea (Sea of Japan) and a major iron- and steel-producing center; other manufactures include textiles, ships, and chemicals. The city was occupied (1910-45) and developed rapidly as an industrial center by the Japanese. It was further developed as a center of heavy industry by North Koreans after World War II. Population (2007 estimate) 754,100.