Abstract: The effects of light intensity and nitrogen limitation on cell growth and cell composition of Chlorella sorokiniana was investigated in this study.The results showed that a high light intensity could significantly improve biomass productivity and carbohydrate content of Chlorella sorokiniana,but caused a slight decrease in lipid content and protein content. The highest biomass productivity( 935.6 mg · L^-1·d^-1),protein productivity( 509.8 mg·L^-1·d^-1) and carbohydrate productivity( 256.0 mg·L^-1·d^-1) were achieved at a light intensity of750 μmol·m^-2·s^-1,while the highest lipid productivity( 105.0 mg·L^-1·d^-1) was obtained at a light intensity of450 μmol·m^-2·s^-1. Moreover,nitrogen deprivation was employed to trigger the accumulation of lipid and carbohydrate.It was found that under nitrogen deprivation for 2 days and 4 days,the carbohydrate productivity and lipid productivity of Chlorella sorokiniana could be further increase to 471.1 mg·L^-1·d^-1and 150.6 mg·L^-1·d^-1,respectively.