Abstract: The benthic mollusca community structure at eleven sampling sites in Huaihe River was investigated in March, June, September and December 2011. A total of 26 species from 9 families were recorded. Thereinto, only 3 species occurred in the first upriver site: Tongbaijinzhuang, and 15 species occurred in the downriver site: Xinchengkou. There were remarkable correlations between water depth and the number of species (r=0.617, P=0.043, n=11), and water depth and density (r=-0.654, P=0.029, n=11). Consequently, the number of species showed a certain increasing trend from upriver to downriver sites. The results of One-way ANOVA showed that there were insignificant seasonal variations in three biocenotic indices (Shannon-Wiener diversity index F(3, 40) =0.225, P=0.879, Margalef index F(3, 40)=0.902, P=0.449, and Pielou evenness index F(3, 40)=0.841, P=0.479) and biomass F(3, 40) =1.931, P=0.14, but not in density F(3, 40) =5.45, P=0.003. The mean maximal density (90.13 36.31) ind./m2 occurred in June while the minimum (14.42 2.78) ind./m2 appeared in December. different with the former, the mean maximal biomass (155.08 50.43) g/m2 occurred in September while the minimum (39.15 14.08) g/m2 appeared in March. The results of One-way ANOSIM showed that there was no remarkable seasonal change in mollusca community structure at density and biomass composition (both P 0.05). The average dissimilarity of density between months ranged from 53.87% to 59.12%, while from 58.76% to 68.58% in biomass. Redundancy Analysis (RDA) showed that river width, water depth and the type of substrate were the main environmental variables deciding the spatial distributions and species richness in Huaihe River.