Sham Chun River (also called Shenzhen River or Shenzhen He) serves as the natural border between Hong Kong and Mainland China, together with the Sha Tau Kok River.

It formed part of the limit of the lease of the New Territories in 1898 in the Convention for the Extension of Hong Kong Territory (also Second Convention of Peking).

It lies in the North District of Hong Kong, and the city of Shenzhen, Guangdong. Its source is at Wutong Mountain, Shenzhen. Its tributaries includes Ping Yuen River, Shek Sheung River, Sheung Yue River, Ng Tung River, Buji River and Tan Shan River. The Shenzhen Reservoir also flows into the river when it is full.

The river flows into Deep Bay (also known as Hau Hoi Wan and Shenzhen Bay). The Mai Po Marshes is at its estuary.

Efforts have be paid to alleviate the flooding and pollution problems. Part of its course was straightened, leading to a shift of boundary. Some one square kilometer of land became Hong Kong's territory after the works.