Abstract: In order to explore the requirement of sugar and nitrogen sources in the vegetative growth and oil production of limacinum Schizochytrium mutant strain,this study determined the change of carbon source and nitrogen source at different fermention stages,and the experimental groups oligosaccharide- adding were set up at five different periods,and the biomass and oil production of each group were measured.The research showed that the first 96 h was the important period of the limacinum Schizochytrium growth,and the biomass increased rapidly.When it was fermented for 144 ~ 168 h,the oil yield reached at the maximum value.The total biomass,lipid production,DHA content and DHA production were comprehensively measured after fermenting for 7 d.The result showed that it was the optimal time to adding oligosaccharide when fermented for 120 h,and the yield of oil and DHA were increased by 18.80% and 22.44% compared with the control group.When the nitrogen source was depleted,oligosaccharide supplement can not only promote the production of oil,but also benefit the formation of DHA.