Data in November 2012, February 2013, May 2013 and August 2013 of Dongshan Bay zooplankton were analyzed by primer statistical software. Results indicate that zooplankton were clearly divided into the outer bay community, Zhangjiang community, estuarine community and inner bay communities. Different zooplankton communities varied in abundance composition, seasonal variations of species and seasonal variations diversity. Zhangjiang communities were most affected by the diluted water, species are mainly Oikopleura dioica,Oikopleura rufescens,Paracalanus parvus and Tortanus dextrilobatus; Estuarine communities in the brackish region, Acartia pacifica is the main species with little seasonal change in number and diversity; The inner bay community was dominated by Acartia pacifica,Paracalanus aculeatus and Calanus sinicus; Sagitta enflata,Subeucalanus subcrassus and Paracalanus aculeatus constitute the most important species abundance in bay communities. Throughout the four seasons' changes of dominant zooplankton species in different communities, the difference of dominant species in four communities in November 2012 and February 2013 is not obvious. In May 2013 and August 2013,in four communities, the dominant species were significantly different.