The Box-Behnken design and response surface methodology (RSM) were employed to optimize the process parameters of supercritical carbon dioxide extraction of the passion fruit seed oil and the antioxidant activities of the extracts was also investigated in this study. Results obtained from the RSM showed that the optimum extraction process parameters within the experimental ranges would be the extraction temperature of 53.1 ℃, pressure of 33.9 MPa, and extraction time of 3.6 h. Under these conditions, the oil yield was 26.95%. The results of the antioxidant experimental also showed that the extracted oil have a potent reducing power and the relative antioxidant ability of oil to scavenge the DPPH· radicals was found to be 80%. Based on these results it can be concluded that supercritical carbon dioxide extraction could be applied to the oil extraction of the passion fruit and the extracted oil have shown promise as a natural antioxidant resource.