Plankton, with large quantity, small size and high diversity, have an important impact on the function of freshwater ecosystem. To explore the community characteristics of zooplankton (including rotifers, cladocerans and copepods) in Poyang Lake, the largest freshwater lake in China, and their relationships with environmental factors, 50 sample sites were set up in Poyang Lake. Zooplankton community and environmental survey were conducted in August (Summer) and November (Autumn) in 2017, February (Winter) and May (Spring) in 2018, respectively. The statistical results showed that 99 taxa belonging to 43 genera were identified, of which 83 species in Rotifera belonged to 31 genera, 11 species in Cladocera belonged to 8 genera, and 5 species in Copepoda belonged to 4 genera. Species were abundant in spring and summer. Zooplankton abundance in four seasons were significantly different with a mean abundance of 1155.29 ind./L. Zooplankton abundance in summer (3150.37 ind./L) was significantly higher than that in other seasons. A total of 14 dominant species were identified in all seasons. The most dominant species in rotifers was Polyarthra vulgaris, and Bosmina coregoni in crustaceans was dominant only in autumn. The dominant species obviously shifted among seasons and the seasonal turnover rate from summer to autumn (86.00%) was higher than that in other seasons (77.00%, 66.67%). The results of dominant species composition, diversity and evenness indexes suggested that zooplankton community structure in Poyang Lake was complex and stable. Cluster analysis and classification and regression trees (CART) showed that there were several community types in each season, among which the division of zooplankton community types in both spring and summer was closely related to Chla, and chemical oxygen demand (COD) was the key factor affecting community division in autumn. Non-metric multidimensional scaling (NMDS) and redundancy analysis (RDA) indicated that Water temperature (WT), Chla, Conductivity(Cond) were main factors related to significant differences in zooplankton communities among seasons. Redundancy analysis (RDA) showed that Total Nitrogen(TN), Total Suspended Solids(TSS) and pH were also important factors affecting zooplankton community structure and distribution of dominant species.