In order to investigate the phytoplankton community structure and water quality, the sampling sites in Yihe River Longmen section were sampled 4 times in 2013 March, July, October, and December.The results indicate that 105 species of 7 phyla of phytoplankton were identified, including 52 species of Chlorphyceae, 23 spe-cies of Bacillariophyte, 21 species of Cyanophyta, 4 species of Euglenophyta, 2 species of Dinophyta, 2 species of Xanthophyceae, 2 species of Cryptophyta.Results from combining the phytoplankton community structure, physico-chemical index and biodiversity index show the water quality of Yihe River Longmen section is medium nutrient type, which reaches the water quality standard of class III surface water.
Yihe River Longmen sectionphytoplanktonwater quality