The Zi Jiang (also Zishui River or Zi River; S.Chinese: 资江 or 资水; T.Chinese: 資江 or 資水; pinyin: zī jiāng; Wade-Giles: Tzu¹-chiang¹) is one of the four largest rivers in Hunan province of China, also one of the main tributaries of the Yangtze River.