From 2017 to 2020, the biological resources of fish, plankton and aquatic macrophytes in the mainstream of Hanjiang River were investigated and analyzed. The results showed that: a total of 98 species of fish were collected, among which the economic fish were mainly carp, crucian carp, silver carp, bighead carp, grass carp, etc.; a total of 116 species of phytoplankton belonging to 71 genera, 7 phyla, among which 46 species were Chlorophyta, and 12 dominant species were bacillariophyta. 86 species of zooplankton belonging to 55 genera were detected, among which 48 species were rotifers, and 8 species were dominant, mainly protozoa. There are 29 species of aquatic macrophytes belonging to 24 genera and 16 families. Compared with the monitoring data in the past, the fish species in the main stream of Hanjiang River decreased, the catch miniaturized obviously, and the fishery resources declined; the species, density and biomass of phytoplankton increased; the species of zooplankton decreased, but the density and biomass increased; the species of aquatic macrophytes decreased. The above changes are related to the construction of water conservancy projects, the change of hydrological regime and the acceleration of water eutrophication. It is suggested to strengthen the protection of fishery resources and environment in Hanjiang River.