Abstract: To investigate the community structure of macrozoobenthos in Yilong Lake and its response to aquatic environmental changes, sampling and identification of macrozoobenthos were conducted in the wet season (July) and the dry season(November) of 2023, with 10 water quality parameters measured simultaneously to analyze the relationship between water quality indicators and the macrozoobenthic community.The results indicate that a total of 64 macrozoobenthic species were identified from Yilong Lake, belonging to 5 phyla, 16 families, and 33 genera.The dominant groups were chironomid larvae (32 species, 50%), oligochaetes (11 species, 17.19%), and crustaceans (7 species, 10.94%), followed by other aquatic insects (9 species, 14.06%, excluding chironomids), mollusks (3 species, 5%), and others (2 species, 3%). The top three dominant species were Limnodrilus hoffmeisteri, Tanypus sp. A, and Macrobrachium superbum.The average density and biomass of macrozoobenthos were 313.72 ind./m² and 51.73 g/m², respectively. Non-parametric tests revealed no significant seasonal differences in density or biomass of various macrozoobenthic groups between the wet and dry seasons, though both total density and biomass were higher in the wet season than in the dry season. Spatially, the density was significantly higher in the central lake area more than in the littoral zone, whereas biomass showed the opposite trend. The Shannon-Wiener diversity index and Margalef richness index of the macrozoobenthic community were significantly lower in the wet season than in the dry season, while no significant difference was observed in the Pielou evenness index. Redundancy analysis (RDA) and Monte Carlo permutation tests revealed that turbidity (f=2.6, p<0.010) was the primary factor influencing macrozoobenthic community variation in the wet season, with water temperature (f=3.4, p=0.040) as a secondary factor. In the dry season, pH (f=4.2, p=0.018) emerged as the dominant influencing factor.