Abstract: We took the phytoplankton summer survey of Zhalong wetland on 8 sampling points, in July,2014.There were 6phylas and 95 speicies（including varieties, forms）.Chlorophyta and bacillariophyta were the major part of the phytoplankton.By using the method of functional group classification, the phytoplankton was divided into 22 different functional groups.There were twelve common functional groups（functional group frequency was greater than 65%）, MP、P、D、C、J、Lo、F、N、X1、X2、W1、TD. MP, P, D, C can be detected at each sampling point. In addition, 1# P and D were dominant functional groups; 2# J and C are the dominant functional groups;3# J、C and MP were dominate functional groups; 4# P and MP were the dominant functional groups; 5# Lo and N were dominate functional groups;6# MP、P and N were dominate functional groups;7# P and MP were the dominant functional groups; 8# P and D were dominate functional groups. What＇s more, based on the Q index method, we evaluated the water quality of the functional group. The relationship of the Q value was 7#6#8# 5# 4# 3# 1# 2#.The evaluation results were：1# and 2# were medium; 3# was good quality;4#、5#、6#、7#、8# were excellent quality, just slight pollution. This result was consistent with the result of diversity index and evaluation.