This paper reports the diversity of phytoplankton, zooplankton, zoobenthon and aquatic macrophytes in Tiane Zhou  Oxbow and Laohe Oxbow located at the middle reaches of Yangtze  River. The diversity of phytoplankton, zooplankton and aquatic macrophytes in Laohe Oxbow is higher than that in Tiane Zhou Oxbow, the diversity of zoobenthon in Laohe Oxbow is lower than that in Tiane Zhou Oxbow. Along with change from opening to closing of oxbow, the diversity of aquatic organisms in Tiane Zhou Oxbow will be on the increase.