Abstract: Freshwater mollusks in Jianxi River from Fengle in Xundun to Shuixiqiao in Jian'ou were surveyed from January to December in 2018.The results showed that 24 species were identified and they belonged to 8 families and 13 genera.The dominant species were Bellamya aeruginosa Reeve,Bellamya purificata Heude,Rivularia auriculata Martens,Corbicula fluminea Müller and Semisulcospira cancellata Benson.The shell length and the wet weight relationship equations showed these five dominant species were all negative allometric growth.The average density and biomass were(4.59±4.47) ind/m² and(5.219±3.623) g/m² and the spatial distribution of density and biomass were positively correlated with the distance to dam.One-way analysis of variance(ANOVA) showed that the density and biomass among different sites were significantly different(P<0.05) and the seasonal distribution of density showed no significant difference(P>0.05) but significantly different in biomass(P<0.05).The community diversities were low.Margalef index,Shannon-Wiener index and Pielou index showed no significant difference among seasons(P>0.05).The invasive species such as Pomacea canaliculata were found in the site of Shangxikou.Compared with other rivers such as Ganjiang River,Qiantang River and Huaihe River,the number of species,density,biomass and the diversity were low.So it is suggested that relevant departments should strengthen the protection of freshwater mollusks resources and habitats,as well as the dynamic monitoring and control of invasive species.