Abstract:Ultrasonic assisted method was used to extract total flavonoids from Amomum tsaoko. Through the single factor experiment and orthogonal experiment， the best conditions to extract flavonoids were found. At the same time，using the assay system of 1，1-Diphenyl-2-picryl-hydrazyl（DPPH）， the antioxidant activities of the Amomum taroko flavonoids were studied and compared with those of VC. Results showed that optimum extraction conditions for total flavonoids from Amomum tsaoko was that volume fraction of 60 % ethanol， ratio of material to liquid was 1 ∶ 50（g/mL）， the temperature was 40 ℃， the ultrasonic power was 160 W and the extraction time was 60 min. On this conditions， the total flavonoids extraction quantity was 24.2 mg/g. The Amomum tsaoko flavonoids and VC both have strong DPPH radical scavenging ability， and the scavenging activity was VC >Amo－ mum tsaoko flavonoids， and the IC50 amomum flavonoids was 12.89 mg/L， the IC50VC was 6.94 mg/L， the DPPH radical scavenging rate of was 80.5 %.