Abstract: From July 2017 to June 2018，the primary production of phytoplankton in Xiangxi Bay was estimated by the method of directly obtaining the dissolved oxygen value of water body with high frequency dissolved oxygen meter. The seasonal variation of phytoplankton primary production and its driving factors in Xiangxi Bay were discussed. The results show that the trends of the values of primary production(GPP, NPP, R) are the same in the four seasons of a year, which are the highest in summer, the second in spring, the lowest in autumn and the last in winter, GPP、NPP、R have significant differences between the four seasons (Mann Whitney u test, P < 0.001). GPP ranged from 0.04 to 24.28 mg O₂ L^-1 d^-1；NPP ranged from -3.78 to 4.92 mg O₂ L^-1 d^-1；and R ranged from 0.01 to 16.87 mg O₂ L^-1 d^-1. The results of the generalized linear model show that there is a positive correlation between chlorophyll a (Chl a), total nitrogen (TN) and gross primary production (GPP), but a negative correlation between soluble silicon (DSI) and gross primary production (GPP); a positive correlation between chlorophyll a (Chl a), water temperature (WT) and respiratory consumption (R), and a negative correlation between soluble silicon (DSI) and respiratory consumption (R); we found no significant correlation with NPP.