Abstract: To develop polysaccharide by microwave-assisted extraction technique and test its antioxidant activity. The polysaccharide was extracted from tree peony seed meal, and that was determined by 3, 5-Dinitrosalicylic acid, to investigate extraction time, extraction power, seed meal granularity and the ratio of material to water. Based on these experiments, finally the orthogonal experiments were to optimize extraction condition. Meanwhile, the ability of polysaccharide to scavenge hydroxyl radical was studied to make a preliminary determination of its biological activity. The results showed the effect order of each factor on yield was as follows:stock ratio>extraction power>seed meal granularity>extraction time and the optimal extraction conditions of polysaccharide were 480 W microwave power for 8 min in combination with stock ratio 1:25 (m/v)and the size of granularity among 120 items, by which the yield of polysaccharide was up to 9.21%. The crude polysaccharide from tree peony seed meal could scavenge DPPH radical and inhibit lipid peroxidation of polyunsaturated fatty from yolk lipoprotein. Thus, the polysaccharide from tree peony seed meal could be developed as a new type of anti-oxidants. This study has provided a technical basis for further development of tree peony seed meal polysaccharide functions and utilization of tree peony resources.