Abstract:In order to extract and isolate the flavonoids from Crotalaria ferruginea，the antioxidant ability of flavonoids was studied.On the basis of single-factor test，the content of total flavonoids was used as the responsive values，extraction time，ethanol concentration and material-to-liquid ratios were set as the main influencing factors，response surface methodology were used to optimize the extraction process of total flavonoids from Crotalaria ferruginea.The antioxidant capacity of total flavonoids from optimal extraction method was studied by DPPH free radical，reducing power and H2O2free radical scavenging activity.The optimal extraction conditions of total flavonoids by response surface methodology were extraction time of 92 second，ethanol concentration of 60%and material-liquid ratio of 1 ∶35（g/mL）.The content of flavonoids was 21.414 2 mg/g.Results of antioxidation showed that the total flavonoids had a good ability to scavenge radicals and had good antioxidant activity in a dose-dependent manner.The stable and reliable method was used for the extraction and antioxidant determination of total flavonoids of Crotalaria ferruginea，which provides some basis for the further development and application of Crotalaria ferruginea.