Abstract:23.4%和66.85%。Based on the single factor test, the effects of particle size, SC CO2 flow rate, pressure, and temperature, extraction time on oil extraction yield were investigated. As a result, three independent variables, such as particle size, pressure, and temperature, have significant effects on the oil yield. A three-factor and five-level second-order regression for central composite experimental design was employed to study the response, and the interaction of the factors on the oil yield was also investigated. By the analysis of response surface, a polynomial regression equation was obtained, to gain the optimal conditions of SC CO2 extraction followed as, particle size of 60 mesh, CO2 flow rate of 20L/h, extraction pressure of 35MPa, temperature of 45℃, and time of 120min. In the aboved condition, the experimental yield of the Paeonia suffruticosa Andr. seed oil is 24.22%. GC-MS analysis shows that the extracted oil is abundant in unsaturated fatty acid with the majority of the components as linoleic acid (23.34%) and linolenic acid (66.85%).