Abstract: To increase yield of puerarin, enzymatic hydrolysis assisted ultrasonic extraction was used to extract puerarin from Kudzu. A Box- Benhnken design ( BBD) involving three main variables such as solid- liquid ratio, enzymatic time and enzyme dosage at three levels was employed based on single factor experiments.The optimal values of these variables were determined by response surface analysis. The optimal conditions were as follows:solid- liquid ratio of 1∶31 ( g / m L) , enzymatic time of 9.8h and enzyme dosage of 31.84 U / g.Moreover, the validity of the established model was verified.The experimental yield of puerarin of 0.728% was in good agreement with the predicted one of 0.723%, which was 15.37% higher than unoptimized group and separately 24.7% and 28.0%higher than ultrasonic extraction and ethanol extraction methods.