Abstract： Objective Optimization of the ultrasonic extraction process of total flavonoids from Picris japoncia.Methods The extraction process of total flavonoids was optimized by response surface method,with the solid-liquid ratio,ultrasonic power,ultrasonic time and ethanol volume fraction as single variables and the total flavonoid content as the evaluation index.Results The optimal ex-traction process was determined as follows:material-liquid ratio 1∶35(g/mL),ultrasonic power 300 W,ultrasonic time 42 min,etha-nol volume fraction 61%.Conclusion The obtained model has good predictability,which provides a basis for the future research of Picris japoncia.