The Ou River or Oujiang is the second-largest river in the Zhejiang province of eastern China. The river flows before finally reaching the city of Wenzhou and emptying into the East China Sea, into which it discharges of water annually. Shen Jiang , Jiang Yongjia , and Wenjiang are all former names for the this river. Ouju, a form of Chinese opera from the city of Wenzhou, derives its name from the Ou River.