［Purposes］ It aims to investigate the plankton community structure, biodiversity, and fish resources in the Puli River Basin of the Three Gorges Reservoir Area, and provide data support for the monitoring and management of the ecological environment in the Puli River Basin. ［Methods］ From March to April 2019, eight sampling sections were set up in the Puli River to conduct investigations and analyses on the plankton community structure and fish resources. The Shannon-Wiener diversity index (H′), Pielou index (J), and Marglef index (D) were used to evaluate the biodiversity of plankton and comprehensively assess the degree of water pollution. ［Findings］ A total of 92 species belonging to 44 genera and six phyla of phytoplanktons were collected in the Puli River, dominated by the Bacillariophyta phylum, which accounted for 60.87% of the total species. The average density and biomass of phytoplanktons were 4.0×104 individuals·L -1 and 0.061 9 mg·L -1, respectively. The average values of H′, J, and D for phytoplanktons were 2.244 0, 0.896 8, and 2.961 7, respectively. A total of 28 species belonging to 21 genera and four phyla of zooplanktons were collected, dominated by the Rotifera phylum, which accounted for 53.57% of the total species. The average density and biomass of zooplanktons were 246 individuals·L -1 and 3.684 7 mg·L -1, respectively. The average values of H′, J, and D for zooplanktons were 1.370 4, 0.889 5, and 1.326 7, respectively. A total of 24 species belonging to five families and three orders of fish were identified in the Puli River, dominated by the Cyprinidae family, which accounted for 62.5% of the total species. ［Conclusions］ The overall water quality of the Puli River Basin ranged from clean to moderately polluted, and the fish resources were significantly reduced compared to historical survey records. Therefore, it is necessary to strengthen the water ecological management and fishery resource protection in the Puli River Basin.