Phytoplankton growth rates and mortality rates were experimentally examined at 21 stations during the 2017spring intermonsoon (April to early May) in the north and central South China Sea (SCS) using the dilution technique,with emphasis on a comparison between the north and central SCS areas which had different environmental factors.There had been higher temperature but lower nutrients and chlorophyll a concentrations in the central SCS than those in the north SCS.The mean rates of phytoplankton growth (μ0) andmicrozooplankton grazing (m) were (0.88±0.33) d–1 and (0.55±0.22) d–1 in the central SCS,and both higher than those in the north SCS with the values of μ0 ((0.81±0.16) d–1) and m ((0.30±0.09) d–1),respectively.Phytoplankton growth and microzooplankton grazing rates were significantly coupled in both areas.The microzooplankton grazing impact (m/μ0) on phytoplankton was also higher in the central SCS (0.63±0.12) thanthat in the north SCS (0.37±0.06).The microzooplankton abundance was significantly correlated with temperature in the surface.Temperature might more effectively promote the microzooplankton grazing rate than phytoplankton growth rate,which might contribute to higher m and m/μ0 in the central SCS.Compared withtemperature,nutrients mainly affected the growth rate of phytoplankton.In the nutrient enrichment treatment,the phytoplankton growth rate (μn) was higher than μ0 in the central SCS,suggesting phytoplankton growth in thecentral SCS was nutrient limited.The ratio of μ0/μn was significantly correlated with nutrients concentrations inthe both areas,indicating the limitation of nutrients was related to the concentrations of background nutrients in the study stations.