Abstract: To study explore the best extraction process and antioxidant capacity of rosmarinic acid（RosA） in Perilla meal（the residue of Perilla seed oil extraction）, and provide theoretical basis and reference basis for the development of RosA resources of Perilla meal, RosA was extracted by ultrasonic assisted extraction method. Single factor tests were carried out on ethanol volume fraction,solid-liquid ratio, ultrasonic power and ultrasonic time. According to the test results, Box-benhnken response surface was designed to optimize the RosA extraction process. The content of RosA was determined by HPLC. DPPH and ABTS⁺free radical scavenging methods were used to evaluate the antioxidant free radical scavenging ability of ultrasonic RosA, Soxhlet RosA, vitamin C（Vc） and watersoluble vitamin E（VE） in vitro. The results showed that the optimum extraction process of RosA was as follows: ethanol volume fraction 50%, solid-liquid ratio 1 ∶ 50（g/mL）, ultrasonic power 150 W, ultrasonic time 35 min. Under these conditions, the yield of RosA was 7. 41%±0. 09%, which was not significantly different from the theoretical value of 7. 53%. The order of DPPH and ABTS⁺ radical scavenging was Vc ＞ ultrasonic RosA ＞ Soxhlet RosA ＞ VE.