Abstract: Response surface methodology was used to optimize the ultrasound-assisted extraction of total triterpenoid saponins from Chaenomeles speciosa. The extraction efficiency of total triterpenoid saponins was investigated with respecting to four variables including time, temperature, ethanol concentration and liquid-to-solid ratio. On the basis of a series of one-factor-at-a-time experiments, a polynomial regression model equation was fitted by the combined use of Box-Behnken experimental design and regression analysis. By analyzing the regression model using response surface analysis, the optimum extraction conditions of total triterpenoid saponins from C. speciosa were identified as follows: 61.69 min extraction time, 62.34 ℃extraction temperature, 70.49% ethanol concentration and 1:30.57 g/mL solid-to-liquid ratio, and the extration efficiency of total triterpenoid saponins was up to 1.55% under the optimized conditions. Confirmatory experiments indicated the good prediction ability of the established model.