The benthic macro invertebrate resources in the islands of the Changjiang estua ry were surveyed,and their ecological characteristics were studied.The results show that there were 41 species of benthic macro invertebrates on the tidal flat wetland of the three islands.The dominant species were Corbicula fluminea,Potamocorbula ustulata,Sinonovacula constricta,Helice tridens tientsinensis,and Ilyrplax deschampsi.The ecological characteristics and environmental function of the benthic invertebrate resources in the islands were analyzed.The species composition and ecological distribution of the islands in the Changjiang estuary reflected ecological characteristics in estuarine.The wetland benthic fauna in the three islands of the Changjiang estuary can be divided into three categories,i.e.fresh water species,brackish water species and sea water species,which reflected the characteristics of eco environmental transitional zone in the estua ry.The species composition and number of zoobenthos in the wetland of the islands was related to sediment composition,sedimentary rate and topography of tidal flat closely.In the tidal flat wetland of the three islands,distribution pattern of benthic fauna in space reflected its success process with the elapse of time.According to the ecological succession of vegetation and the characteristics of fauna,tidal flat wetland in the Changjiang estuary may be divided into three ecological sere,i.e.saline algae zone,bulrush community zone and reed community zone.Many species of zoobenthos have great economic value,which are principally some species of Crustacean and Mollusc.Zoobenthos in the wetland of the three islands play an important role in the estuarine ecosystem such as transporting trophic material and transforming pollutants,acting as significant channel of energy flow,and influencing on the movement and stability of sediments.Finally,some suggestions for developing and conserving the benthic invertebrate resources were proposed.