In order to demonstrate macrozoobenthic community structure dynamics and conduct a biological evaluation of water quality in Qingcaosha Reservoir, seasonal samples were collected from January to December 2014 at 11 sampling sites. A total of 22 species belonging to 4 phyla, 14 families, and 19 genera were identified, including 7 polychaeta, 4 oligochaeta,3 arthropod, 5 molluscs and 1 nematomorpha. Dentinephtys glabra, Goniada japonica and Corophium volutator were the dominant species in Qingcaosha Reservoir. The mean annual density and biomass of macrozoobenthos were (160.30±90.15) ind/m² and (0.52±0.35) g/m², respectively. There were no significant differences in the macrobenthic density and biomass among the sampling sites and seasons (P>0.05). Based on the macrozoobenthic biodiversity index, biological pollution index (BPI) and Hilsenhoff biotic index (BI), there were no significant differences between stations and seasons. ABC curves, hierarchical clustering and MDS were used to analyze the data of community structure. The results showed that Qingcaosha Reservoir, suffering less disturbance, keeps a stable community structure.