Abstract: Abstract: The aim of the study was to get the best condition of multiplication culture of Tripterygiium Wilfordii Hook.f., the multiplication medium of Tripterygiium Wilfordii Hook.f. was optimized with quadratic orthogonal combination design. The results showed that the quadratic orthogonal recursive model of multiplication rate(y) to three concentration factors of MS(x1), 6-BA(x2) and NAA(x3) is y=6.98483-0.25481x12-0.51998x22-0.37856x32-0.35x1x2-0.325x2x3. The results showed that the low concentration of MS, 6-BA and NAA promoted the rate of multiplication and the high concentration inhibited it; and that the rate of multiplication was more than 6.3 with the probability of 95% when the MS concentration was in range of 0.398 to 0.602 MS, 6-BA in 0.919 to 1.092 mg/L and NAA in 0.167 to 0.233 mg/L.