Jiangsu consists largely of the alluvial plain of the Chang River and includes much of its delta; in elevation it rarely rises above sea level, although there are hills in the southwest. The fairly warm climate, moderate rainfall, and fertile soil make Jiangsu one of the richest agricultural regions of China and one of the most densely populated. The province straddles two agricultural zones, with wheat, millet, kaoliang, corn, soybeans, and peanuts cultivated in the north and rice, tea, sugarcane, and barley raised in the south. Cotton is grown along the coast (north and south) in the saline soil, which is not suited for other crops. Tea is planted in the western hills, and some experimenting with oak trees for silk culture has been initiated.

Intensive land reclamation has been accomplished, with extensive dikes and the use of the raised-field system. Fish are abundant in the many lakes (of which Tai is the most famous), in the streams and canals, and off the Chang River (Yangtze) delta; Jiangsu, which is known to the Chinese as the land of rice and fish, is rich in marine products. It is also a major salt-producing area. Jiangsu is bisected by the Chang, which can be navigated by steamers up to 15,000 tons, and by a portion of the Grand Canal. Its first-class roads and extensive railroad system, including the busiest railway in China, the Shanghai-Nanjing line, make for excellent communications. Perhaps the most prosperous province in China, Jiangsu is deficient only in timber and minerals.

A major part of China's foreign trade clears through the port of Shanghai into Jiangsu. Shanghai, one of the world's great seaports and the chief manufacturing center of China, is in Jiangsu province but is an independent municipality administered directly by the central government. Nanjing has been developed into an industrial center, producing petrochemicals, motor vehicles, machinery, and construction materials. Suzhou, Wuxi, and Zhenjiang are known for their silk. Textile, food-processing, cement, and fertilizer industries are found throughout the province.

Jiangsu was originally part of the Wu kingdom, and Wu is still the province's traditional name. Jiangsu received its present name, derived from Jiangning (Nanjing) and Suzhou (Soochow), in 1667, when it was formed from the old Jiangnan province. The gateway to central China, Jiangsu became the main scene of European commercial activity after the Treaty of Nanjing (1842). The capture of Jiangsu in 1937 was an important phase of Japan's effort to conquer all China (see Sino-Japanese War, Second). Liberated by the Chinese Nationalists in 1945, Jiangsu fell to the Communists in 1949. For a time Jiangsu was administered as two regional units, North and South Jiangsu, but in 1952 the province was reunited. Many archaeological sites have been excavated in Jiangsu since 1956. In 1984 the province was made a part of the Shanghai special economic zone, which has increased investment in and exports from port cities like Nantong.