city and industrial centre in southeastern Anhui sheng (province). Ma'anshan is situated on the south bank of the Yangtze River (Chang Jiang) some 22 miles (35 km) downstream from Wuhu, near the border of Jiangsu province, opposite Hexian. The city is on the railway between Wuhu and Nanjing (Nanking). The area had been under the administration of Dangtu xian (county) since the Sui dynasty (581–618) when in 1956 a portion of the county was set off to establish Ma'anshan city. In 1983 Ma'anshan became a prefecture-level city, with Dangtu under its administration.

The region along the southern bank of the Yangtze between Ma'anshan and Tongling (about 150 miles 【240 km】 upstream) has long been a mining area. The development of a modern metallurgical industry was made possible by the opening of the Huainan coalfield in the mid-1930s and by the construction of the Huainan-Hefei-Yuxikou railway. After 1938, under Japanese occupation, a small steelworks and an iron-smelting plant were established. They were, however, destroyed late in World War II, and the local iron mines—most of whose production had been shipped to Japan—were abandoned.

After 1949 the smelting plant was restored, and it resumed production in 1953. During the First Five-Year Plan (1953–57), Ma'anshan rapidly grew into a major industrial centre. In the early 1950s Ma'anshan's iron production was increased to supply the steel industry in Shanghai. Under the Second Five-Year Plan (1958–62), it was decided to develop Ma'anshan into an integrated iron and steel complex. Other industries subsequently were developed, including the manufacture of machinery, chemicals, construction equipment, and electronic equipment and electric-power generation. Sulfur is also mined in the area. Pop. (2002 est.) 443,484.