1.Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources，Ministry of Education，Shanghai Ocean University，Shanghai 201306，China；2.Institute of Marine Science，Shanghai Ocean University，Shanghai 201306，China
Abstract: In the present study the species composition，species dominance and characteristics of macrobenthic fauna were investigated and evaluated in 10 sampling stations from four survey cruises in Yangtze River estuary on September，October，November and December，2012 to understand the environment in shoals of the Yangtze River estuary and adjacent regions by the Shannon-Wiener diversity index（H′），Pielous species evenness（J），species abundance（d），and Berger-Parker dominance index（Y）.A total of 37 macrobenthic species were found in tidal flats of Yangtze River estuary in 2012，with dominant benthic fauna of crustaceans，molluscs and polychaetes，average biomass of 13.33 g/m2in the tidal flats of Yangtze river estuary during four months，and average abundance of 50.06 ind./m2.The index H′was ranged from 1.35 to 1.89，the J value ranged from 0.40 to 0.54，and the d value varied from 4.64 to 5.16.There was the maximal biomass and abundance of molluscs in the macrobenthic fauna tested，with the dominant species of Elachisina sp.，Sesarma dehaani，Helice tientsinensis and Corophium yolutatator.The hierarchical clustering and nonmetric multidimensional scaling analysis（NMDS）revealed that the macrobenthic community in Yangtze River estuary was divided into two groups，September and October group，and November and December group.Abundance and biomass comparison（ABC）curves indicated that macrobenthic community was heavily affected in November and December，and moderately affected in September and October，indicating that more attention is needed to pay to the benthic ecosystem in Yangtze River estuary due to the unfavorable interference with the macrobenthic community and diversity.
2016, Vol. 31 
