Abstract:The ultrasonic-assisted extraction of total flavonoids from Wuyuan imperial chrysanthemum using deionized water as the extraction solvent was optimized on the basis of a single factor experiment and a Box-Behnken response surface analysis.Additionally，the antioxidant capacity of the total flavonoids purified was studied.The optimal extraction parameters were as follows:liquid-to-solid ratio，24∶1（mL/g）；ultrasonic time，31 min；and ultrasonic power，200 W.Under these conditions，the total flavonoid extraction rate was 3.641%.The antioxidant assays revealed that the DPPH free radical scavenging activity，hydroxyl radical scavenging activity，and superoxide anion scavenging activity of the total flavonoids from Wuyuan imperial chrysanthemum were similar to those of L-ascorbic acid.