The Xin River (Chinese: 信江; pinyin: Xīn Jiāng; Wade–Giles: Hsin Jiang) flows in Yushan County from the eastern edge of Jiangxi Province of central China into Poyang Lake.

The headwaters at 28°59'N 118°05'E are in the Huai Shan mountains in the north and eastern boundaries of its watershed from which the river flows west.

Huanggang Shan is 2,158 m tall,[4] the highest mountain in Jiangxi Province, on the southern edge of the basin.

In the Poyang Lake area downstream the river enters a flat open alluvial plain.

Likewise, 40% of the Xin River basin, in the east end, is mountainous and the rest of the area is hills (35%) and plains (25%).

Rainfall generally begins in April and gradually increases with some areas receiving up to 2000 mm or more annually.

In recent years, with the economic development of the basin, addressing the pollution of the river channel has become increasingly important.