Objective:Box-Behnken experimental design was used to optimize the ultrasonic-assisted extraction process of the total flavonoids fromFructus Aurantii.Methods:Taking the extraction yield of total flavonoids from Fructus Aurantii as indexes，the single factor experiment and Box-Behnken experiment design were used to optimize the ethanol concentration，extraction time and material-to-liquid ratio.Results:The optimal condition established in this experiment was ethanol concentration of 14%，ultrasonic extraction time of 27 min，and material-to-liquid ratio of 1∶44. Under these optimal conditions，the extraction yield of the total flavonoids of Fructus Aurantii was 18.81 mg·g-1，which was in line with the predicted value of the model.Conclusion:Ultrasound-assisted extraction of total flavonoids from Fructus Aurantii is feasible with less time and higher extraction yield. This study provide the foundation for further research on Fructus Aurantii.