[Purpose] Study on Extraction of Lysimachia christinae polysaccharide. [Method] The polysaccharide was extracted by ultrasonic method, its reducing power, ?OH, the ultra oxygen anion scavenging ability of study. [Results] Within a certain range of research, with the increase of concentration of polysaccharide, polysaccharide ?OH, the ultra oxygen anion scavenging ability enhancement. [Conclusion] Lysimachia christinae Hance polysaccharide has a strong antioxidant capacity.