[Objectuve] The aim of the study was to optimize extraction technology of polyphenol in stem of Poacynum hendersonii and study its antioxidation in vitro.[Method]The extraction technology of polyphenol was optimized by response surface analysis and the effect of liduid ratio,extraction time and ultrasonic intensity on extraction yield of polyphenol was investigated. V_Ctaken as reference,antioxidant activity of polyphenol in Poacynum hendersonii and tea were compared and analyzed.[Result] The optimal extrac...