Abstract: In order to grasp the ecological status of Tangxun Lake in Wuhan City to identify major ecological problems, 9 points were set up in Tangxun lake area in 2019, the structure changes of plankton community and water quality were monitored and analyzed. The results showed that in the total composition of phytoplankton community in Tangxun Lake water body, a total of 34 species of algae were identified, including 8 species of Diatomaceae, 7 species of Cyanophyta,14 species of Chlorophyta, 2 species of Cryptophyta, 3 species of Euglena; and a total of 14 species of 2 types of zooplankton were detected, including 8 species of Copepods and 6 kinds of Cladocerans. Phosphorus was the most important environmental factor affecting the density of phytoplankton in Tangxun Lake. The top-down effect of zooplankton on phytoplankton was the most important biological factor affecting the growth of phytoplankton in Tangxun Lake.

Key words: phytoplankton, cyanobacteria blooms, zooplankton, top-down effects, Tangxun lake