Abstract: Epimedium residue which was firstly conducted to extract flavonoid was applied to extract polysaccharide. In addition, the total contents of carbohydrate, uronic acid and protein of Epimedium residue polysaccharide were measured by chemical methods, and the structural characteristic of ERP was detected by FT-IR spectra. Furthermore, DPPH, superoxide anion radicals, hydroxyl radical scavenging abilities of ERP were analyzed for antioxidant activity in vitro. The results showed that the contents of carbohydrate, uronic acid and protein were 73.39%, 6.33% and 1.87%, respectively. The maximum inhibition percentage of DPPH, superoxide anion radicals and hydroxyl radical of ERP were 79.96%, 92.77% and 69.12%, respectively. The IC50 values of those antioxidant activities were 0.26, 0.03, 0.76mg/mL, respectively.