Abstract: ObjectiveThe extraction conditions of total flavonoids from pitaya was optimized , in order to provide a theoretical basis for comprehensive development and utilization of pitaya. MethodUsing red-peel red-pulp pitaya as ma-terial, based on single-factor experiment, the ethanol refluxing extraction process of total flavonoids from pitaya was opti-mized using orthogonal experiment design. Meanwhile , the ultrasonic-assisted extraction process was optimized using re-sponse surface methodology. ResultThe results showed that, the optimal conditions of ethanol refluxing extraction were 80%ethanol, 80℃of extraction temperature, 1∶25 of solid-to-liquid ratio, and 2 h of extraction time. Under those opti-mal conditions, the yield of total flavonoids from pitaya was 18.07 mg/g. The optimal conditions of ultrasonic-assisted ex-traction were as follows:250 W of ultrasonic power, 20 min of ultrasonic time, 1∶25 of solid-to-liquid ratio, 80%ethanol, and 80℃of extraction temperature. Under those optimal conditions, the yield of total flavonoids was 19.58 mg/g. Con-clusionThe ultrasonic-assisited extraction is simple, time-saving, high-efficiency, and better than ethanol refluxing ex-traction. Therefore, the ultrasonic-assisited extraction can be used to extract total flavonoids from pitata.