Abstract: Investigating the community structure of zoobenthos and carrying out biological assessment of water quality are of great significance to the formulation of watershed environmental management strategies. Through the investigation on zoobenthos in the Maotiao River Basin, the secondary tributary of the Yangtze River, 82 species of zoobenthos were found, belonging to 4 phyla, 7 classes and 51 families, among which the number of aquatic insects was dominant. The total average individual density of zoobenthos was 84 ind./m2, and the total average biomass density was 11.01 g/m2; the average Shannon-Wiener diversity index was 1.57, and the average Pielou index was 0.66. The results of biological assessment of water quality indicated that most of the river sections of the Maotiao River were in a polluted state, and the tributaries were more polluted than the main stream. The results of the Shannon-Wiener diversity index and the BMWP scoring method had certain differences. The results obtained by the BMWP scoring evaluation were generally inferior to the results of the Shannon-Wiener diversity index evaluation.