Songjiang, Wade-Giles romanization Sung-chiang, former town in Shanghai shi (municipality), eastern China; it is now a southwestern district of Shanghai. Until 1958 it was a part of Jiangsu province. It takes its name from the Song River (Song Jiang; the present-day Wusong River, the upper stream of the Suzhou River), which flows from Lake Tai to the sea, through Shanghai.
It first became an independent county in 751 under the name of Huating, and in 1278 its name was changed to Songjiang. It was a superior prefecture under the Ming (1368–1644) and Qing (1644–1911/12) dynasties and grew into a large town. Songjiang was originally the centre of a prosperous rice-growing area and, together with Suzhou to the northwest, was a major source of grain revenues. After cotton was introduced under the Mongols in the 14th century, the area produced cotton, and cotton spinning and weaving became a major domestic industry. By the 18th century the quality of the region’s cotton textiles had gained an international reputation. In the 19th century the town was a strategic centre for the defense of Shanghai during the Taiping Rebellion (1850–64) and was badly damaged in the fighting.
The phenomenal 19th-century growth of Shanghai, however, also took away the town’s role as a commercial centre, and in the mid-20th century it became completely dominated by its large metropolitan neighbour. Since the 1980s, however, the rapid growth of Shanghai has brought new development to Songjiang. A new industrial zone, along with a national export-processing zone, has been established there since the 1990s. Enterprises established in the zone include those making electronic machinery, biochemicals, high-technology semiconductor materials, and pharmaceuticals. A large vacation centre has been built northwest of the district near Mount She, providing a holiday resort for numerous metropolitan workers. A number of research centres and universities and colleges have been established in the Songjiang University Town, which was founded in 2000. A new residential district has been under construction north of the old town. Songjiang has excellent waterway communications with the plain around Lake Tai and is also on major rail and expressway routes between Shanghai and Hangzhou in northern Zhejiang province.