Abstract: Four investigations were conducted at the 14 sampling sites in 7 sampling sections in the Jingjiang reach of the Yangtze River in March, June，September and December 2017 respectively to evaluate the relationship between plankton community composition and environmental factors. The results showed that 135 species (including varieties) of phytoplankton belonging to 7 phyla 67 genera were identified, dominated by Bacillariophyta (51.85%) and Chlorophyta (25.19%).The mean density and biomass of phytoplankton were 73.16×104 cells /L and 0.87 mg/L respectively. The difference of phytoplankton abundance and biomass among different sampling sections of upper Jingjian were not obvious, and the abundance and biomass of phytoplankton showed a steady increasing trend from the upper reaches to the lower reaches of lower Jingjiang. The dominant species were Aulacoseria granulate and Cyclotella meneghinian. Margalef richness index, Pielou evenness index and Shannon-Wiener diversity index were 0.83, 0.80 and 1.90 respectively. The richness index and diversity index of the Lower Jingjiang were higher than those of the Upper Jingjiang, which indicated that the pollution of the Upper Jingjiangwas more serious than that of the Lower Jingjiang. Canonical correspondence analysis showed that dissolved oxygen, water temperature and NH3-N were the main factors affecting phytoplankton community structure. A total of 81 species of zooplankton belonging to 48 genera were identified, dominated by Rotifer (37.04%). The mean density and biomass were 6.32 ind./L and 88×10-3 mg/L respectively, and the abundance and biomass of zooplankton in upper Jingjiang were lower than that in lower Jingjiang. The dominant species were Difflugia corona, Copepods nauplii and Cyclops sp. The richness index, evenness index and diversity index of the Lower Jingjiang are higher than those of the Upper Jingjiang, which indicated that the pollution of the Upper Jingjiang is more serious than that of the Lower Jingjiang. Canonical correspondence analysis showed that water temperature， dissolved oxygen and NH3-N were the main factors affecting zooplankton community structure.