The Xi River is the western tributary of the Pearl River in China. It is formed by the confluence of the Gui and Xun Rivers in Wuzhou, Guangxi. It then flows east through Guangdong, and enters the Pearl River Delta just east of the Lingyang Gorge in Zhaoqing. The main branch of the Xi River flows southeast through the delta entering the South China Sea at Modao Men, just west of Macau. The major cities along the Xi include Wuzhou, Zhaoqing, and Jiangmen.