The ultrasonic-assisted extraction process of saponin from Aralia continentalis Kitag was studied.On the basis of single factor tests,response surface methodology was designed by minitab software 15,and the effects of ethanol concentration,ratio of solid to liquid,extraction time and extraction power on the extraction amount was studied.The result showed that the optimum extraction conditions were as follow: with 90% ethanol as the extraction solven and a ratio of solid to liquid of1 /60,extraction power at 250 W for 40 min.The predicted extraction amount was 45.14 mg/g,close to the practical extraction amount of 41.35 mg/g.