Abstract: Based on the single factor experiments,the response surface methodology( RSM) was employed to optimize the conditions of supercritical CO2 extraction of oils from Aurantiochytrium sp..The optimum condition were as follow: extraction pressure of 30.3 MPa,temperature of 64.4 ℃,CO2 flow rate of 56 L / h and extraction time of2 h,under which the oil extraction rate was 74.55%. The main components of oils were palmitic acid and DHA,which were 48.818% and 35.120% of the total fatty acids,respectively.The extracted oils of Aurantiochytrium sp.had simple composition and high DHA content,which can be used as potential resources for health products.