Abstract: Extraction of total flavonoids from wild patrinia villosa and its antioxidant activity determination can make full use of this kind of wild resource and exploit activity component. Single factors experiment and orthogonal array design methods were used to optimize the conditions for ultrasonic-assisted extraction of total flavonoids from wild patrinia villosa. The antioxidant activity of the extract was evaluated by spectrophotometry on its ability of scavenging hydroxyl radical (·OH) , superoxide anion radical (O-2·) and 1-diphenyl-2-picrylhydrazy (DPPH·) , total reducing power. Results indicated that temperature, solid-liquid ratio, ethanol concentration and extraction time significantly affected the extraction percent of total flavonoids. The optimum procedure for ultrasonic-assisted extraction of total flavonoids were ethanol concentration of 80%, extraction temperature of 70℃, ratio of material to solvent of 1∶35, ultrasonic time of 40min and that the flavonoids yield was up to 64. 62mg/g. The scavenging effects of the extract on·OH, O-2·, DPPH· were significant, the extract also had a strong total reducing power. All these activities were concentration dependent.