river, tributary of the Yangtze River (Chang Jiang) system in northeastern Jiangxi (Kiangsi) province, eastern China. The Xin has a length of 194 miles (312 km) and drains an area of about 6,500 square miles (16,800 square km). It rises along the northeastern border of the province and flows southwestward past the city of Shangrao, a commercial centre producing paper and processing tea. The river continues generally westward to Yingtan, where it courses northwestward to empty into Lake Poyang (Poyang, Lake), east of Nanchang. The lower and middle stretches of the river run through an important rice-growing area of China; tea and wheat are grown farther upstream.