Abstract: In order to understand the characteristics of zooplankton community structure in the water ecological function zoning of the Taihu Lake Basin during the normal season, the zooplankton community survey and water quality monitoring were carried out at 201 sampling points in the Taihu Lake Basin in May 2018.122 species of zooplankton were detected, belonging to 49 genera of 3 categories, with the majority of rotifers and cladocera. Class Ⅰ，Ⅱ，Ⅲ and Ⅳ areas are dominated by rotifers. Shannon-Wiener index(H), Simpson index(D) and Pielou index(E) were the largest in Class Ⅰ areas, which were 2.28, 0.84 and 0.47. A total of 19 dominant species were detected, 60 % of which were eutrophic indicating species. The dominant species in Class Ⅱ area were the most. Keratella cochlearis and Brachionus angularis were the most， which affected the water quality in Class Ⅱ area. Canonical correspondence analysis(CCA) results showed that the community structure of dominant zooplankton species was significantly positively correlated with TP and TN. According to Pearson analysis, species in Class Ⅰ，Ⅱ，Ⅲ and Ⅳ areas were significantly positively correlated with TP. With the increase of zoning grade, the correlation with TP was significantly increased, and the correlation with CODMn and TN was also significantly increased. The dominant factor for the change of zooplankton population structure and eutrophication of water body is P. In summary, in 2018, the Taihu Lake Basin was in a eutrophic state in the normal water period, and the water quality was in a medium pollution state. The treatment of algal blooms in the Taihu Lake Basin should be focused on limiting phosphorus emission and reducing TP content. The structure of zooplankton community influences the division of ecological functional zones.