In this study, changes in the yield and free radical-scavenging activity of black sesame oil under different extraction parameters were investigated. An increase in the pressure and the supercritical CO2 flow rate improved the extraction yield, shortened the extraction time and increased the free radicalscavenging activity of extracted oil. The extraction yield increased as the particle size decreased depending on decreasing intra-particle diffusion resistance and increasing interfacial areas. The optimal conditions for extraction of black sesame oil were obtained at 60°C, 350 bar, 45g CO2/min, 315-800 um of particle size and extraction time of 180 minutes.