Spring community structure of phytoplankton from rivers and wetlands in Lake Chaohu catchment was investigated by means of field sampling, and it's relationship with environmental factors was analyzed by detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA).The results showed that 73 species (genera) phytoplankton have been identified in water from Lake Chaohu, which belonged to Bacillariophytas Chlorophyta, Cyanophyta, Cryptophyta, Chrysophyta, Pyrrophyta, Euglennophyta and Xanthophyta, respectively. In the water of Lake Chaohu, 93.5% of the phytoplankton belonged to the phyium Bacillariophyta, Cyanophyta and Chlorophyta, which constructed the dominant population. Notably the number of Anabaenopsis from the phylum Cyanophyta, the most dominant species, is 21.9% of the numbers of the phytoplankton. In some rivers discharged to Lake Chaohu, the dominant species are also of the phylum Bacillariophyta, Cyanophyta and Chlorophyta, which constitute 82.6% of the phytoplankton. The number of Pkormidium (the species of the largest population) reaches as high as 38.3% of the number of the phytoplanJcton, while the number of Apkanisomenon (the species of the second largest population) reaches 32.6%, both of which belong the phylum Cyanophyta. These two species construct the absolute dominant species. A significant discrepancy in spatial distribution of phytoplanton in the lake was observed. Phytoplankton community structure and spatial distribution in the water were remarkably affected by temperature, turbidity and NO₃^--N. However, concentrations of Chi. a, NO₃^--N and PO₄^3--P were the main environmental variables affecting phytopiankton community structure and spatial distributions in water from rivers discharged to the lake.