It separates Yuen Long District, 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.