Based on the data collected in Jiaojiang inshore waters in April,July and November of 2010,the relationship between horizontal distribution and seasonal changes of zooplankton was discussed in this paper. The results showed that horizontal distribution of zooplankton had an obvious seasonal variation and zooplankton abundance peaked in spring (1 700.07 ind/m³), and it was the second highest in summer (258.65 ind/m³), the lowest in autumn (72.90 ind/m³). Jiaojiang runoff and Zhejiang coastal current play an important role in zooplankton abundance as a result of the relevantly weak upwelling in spring and autumn. Obvious variation of the three seasonal dominant species in investigated waters can be observed, Calanus sinicus in spring, Calanus sinicus,Acartia pacifica,Euchaeta concinna and Sagitta nagae in summer and Sagitta enflata and Diphyes chamissonis in autumn are the main species that result in the seasonal changes of phytoplankton abundance. Survey results were compared with the same period of phytoplankton findings of zooplankton, and phytoplankton and zooplankton abundance high value area is not consistent with the nutrient salt and water masses of different seasons of investigation waters changes.