Abstract: The optimum purification of α-linolenic acid from fructus perillae was obtained through response surface methodology (RSM) .Based on the results of single factor tests, the concentration of silver nitrate solution, mass ratio of silver nitrate to fatty acid, volume fraction of methanol were selected as three factors for Box-Behnken design.RSM analysis with three factors and three levels was used to optimize the purification conditions.The optimum condition was obtained as follows:concentration of silver nitrate was 4mol/L, mass ratio of silver nitrate to fatty acid was 4.2:1, volume fraction of methanol was 15.3%.Under this condition the yield of α-linolenic acid was 84.63%, and the purity of α-linolenic acid was beyond 95%.