Abstract: Extracting technique assisted by ultrasonic extraction method of oleanolic acid and ursolic acid from hawthorn was optimized. The total content of oleanolic acid and ursolic acid was used as response value,ratio of liquid to solid,ultrasonic power,and extracting time were investigated in this experiment. The results showed that the sequence of different factors on triterpene content was:ratio of liquid to solid>extracting time>ultrasonic power. The results of variance analysis showed that ratio of liquid to solid and extracting time had extremely significant effect on oleanolic acid and ursolic acid content(p<0.01),ultrasonic power had a significant influence on oleanolic acid and ursolic acid content(p<0.05),extracting time of the quadratic term had extremely significant effect(p<0.01). There was no interaction effect between each factor(p>0.05). The optimal condition was that ethanol volume percentage 90 %, ratio of liquid to solid 35 ∶ 1m L / g, ultrasonic power 352 W, extracting time4.6min. Under the optimal condition,the oleanolic acid and ursolic acid content of hawthorn was 2.87mg/g,which was consistent with the predicted value. Extraction method using in this experiment demonstrated high extraction efficiency and shorter time simultaneously.