Abstract:With Rhizoma imperatae as raw material，the ultrasonic-assisted extraction process parameters of total flavonoids from Rhizoma imperatae were optimized by response surface method.Based on single factor experiments，ethanol concentration，liquid-solid ratio，ultrasonic power and extraction time were selected as influence factors，and response surface methodology was used to optimize conditions of extraction process of total flavonoids from Rhizoma imperatae.The results showed that under the optimum extraction conditions of ethanolconcentration50%，liquid-solidratio25∶1（mL/g），ultrasonic power 530 W and extraction time 30 min，the yield of Rhizoma imperatae total flavonoids was 2.18 mg/g，which approached to theoretical value 2.21 mg/g.This suggests that the response surface method is feasible to optimize extraction process of Rhizoma imperatae total flavonoids.