Yangcheng Lake (Chinese: 阳澄湖; pinyin: Yángchéng Hú) is a freshwater lake about 3 km (1.9 mi) northeast of the city of Suzhou in Jiangsu Province, and ranges in depth from 1.5–2 m (4 ft 11 in – 6 ft 7 in).

It is the most famous area of origin for the Chinese mitten crab, which is considered a delicacy.

It crosses the boundary of the cities Suzhou, Changshu and Kunshan and has a surface area of about 20 km2 (7.7 sq mi).

The 2,310-meter (7,580 ft)-long Yangcheng West Lake Tunnel (阳澄西湖隧道) runs underneath the lake,[2] and the lake itself is served by both a mainline high-speed railway station Yangchenghu railway station and 2 stations of the Suzhou Rail Transit system: Yangchenghu South station on Line 5 and Yangchenghu East on Line 11.

The Chinese mitten crabs migrate from Yangcheng Lake towards the Yangtze delta for mating in September and October.