A study on the phytoplankton in Taipinghu Reservoir in China found that the community was mainly made up of algae from three groups: Chlorophyta, Cyanophyta, and Bacillariophyta. These groups accounted for the majority of the phytoplankton species, cell density, and biomass. The highest growth was observed in summer, with diatoms being abundant near a river and flagellated algae like Euglena and Chromulina in a fish culture bay. The reservoir was classified as mesotrophic with slight natural eutrophication based on algal composition and total nitrogen concentration.