Liaodong Peninsula, triangular peninsula in northeastern China, bounded on the west by the gulf of Bo Hai, on the southeast by Korea Bay, and on the northeast by North Korea. Liaodong Peninsula covers 54,000 sq km (21,000 sq mi) in Liaoning Province. It narrows from a maximum width of 150 km (93 mi) in the north to its southern tip near the port city of Dalian. The backbone of the peninsula is formed by the Qian Shan Mountains, crossing the region from northeast to southwest. Elevations in the peninsula average 500 m (1,700 ft).

A moderate climate, abundant precipitation, and a six-month growing season make Liaodong Peninsula one of the most important fruit-producing regions in China. With 900 km (560 mi) of coastline, the peninsula also contributes significantly to the country's fish catch. In addition, the peninsula has been one of China's major industrial bases since the 1960s. More than 600 large- and medium-sized metallurgical, machine-building, petrochemical, and construction enterprises are located there. Dalian is an industrial center and the largest international port in northern China. In 1988, in order to encourage foreign investment, the Chinese government established a tax-free zone from Dalian to Shenyang, the capital of Liaoning Province. Today several hundred enterprises in the area are foreign-funded, and industrial and agricultural production in the peninsula now accounts for 75 percent of the entire output of the province.