Abstract: Objective:To optimize the extraction process of total triterpenoids from Dischidia chinensis and to study the antioxidant capacity. Methode:Triterpenoids were extracted from Dischidia chinensis by ultrasound and their contens were determinated with spectrophotometry. Firstly, the initial test conditions were determined by single factor test. L₃ (3⁴) orthogonal test was used to optimize the process based on single factor experiment. The antioxidant activity of total triterpenoids extracted after optimization by DPPH·.Results:The effects ability of four factors on the yield of total triterpenoids were as follows:Material-liquid ratio > temperature > ultrasound power > ultrasound time. The optimum extraction process was that the solvent was ethyl acetat, ultrasound time was 30 min, material-liquid ratio was 1:20 (g/mL), ultrasound power was 200 W, temperature was 55℃. And the average yield of total triterpenoids from Dischidia chinensis was 20.82 mg/g. When the concentration of total triterpenoids extracted by this process was 2.00 mg/mL, the DPPH removal rate was 26.86%, but its antioxidant activity was lower than that of V_C. Conclution:Compared with traditional solvent extraction and Soxhlet extraction, the yield of total triterpenoids extracted by the optimized ultrasonic extraction process was obviously higher, and the average yield was 20.82 mg/g. The obtained total triterpenoids from Dischidia chinensis had certain antioxidant activity.