Abstract: We examined the phytoplankton community structure in the Hulin area in the Sanjiang Plain wetland in July of 2014 with 10 sampling sites. We identified 133 taxa belonging to 8 divisions, 10 classes, 16 orders, 27 families, and 48 genera. They were predominantly Bacillariophyta and Chlorophyta. The phytoplankton species composition and abundance was significantly different at each sampling site. Most of the algae were found in the site Ⅸ. While the biomass in sites Ⅱ was greater than that of other sites. We found a large proportion of β-mesosaprobic-zone indicators. Meanwhile, cluster analysis and non-metric multi-dimensional scaling analysis showed that the water in Hulin wetland was of certain degrees of pollution, and the water was at the mesotrophic level.