Anoectochilus formosanus and Anoectochilus zhejiangensis are Anoectochilus plants,they are main original plants of Anoectochilus roxburghii that is common folk rare herbs and they are rich in polysaccharide.The study extracted polysaccharide of Anoectochilus formosanus and A.zhejiangensis using ultrasonic extraction Ⅰ,Ⅱ,solvent extraction methods to compare polysaccharide content;we use colorimetry method to compare hydroxyl free radical clearance ability of the two A.roxburghii.We use Caenorhabditis elegans as a model organism to study the effects of two A.formosanus polysaccharide on lifetime of Caenorhabditis elegans under oxidative stress,then we can evaluate antioxidant activity of A.formosanus and A.zhejiangensis.The results show that:(1)the solvent extraction method is the most effective method to extract polysaccharide of A.roxburghii,polysaccharide content of Anoectochilus zhejiangensisis significantly higher than that of A.formosanus.(2)With the increase of polysaccharide concentration,hydroxyl free radical clearance rate has a tendency to rise,the hydroxyl free radical clearance rate of Anoectochilus zhejiangensis polysaccharide is significantly higher than that of A.formosanus polysaccharide.(3)Both kinds of Anoectochilus polysaccharide can prolong the lifetime of C.elegans,but the impact of two kinds of polysaccharide to the lifetime of C.elegans is not obviously different.The results show that both kinds of Anoectochilus are rich in polysaccharide and have antioxidant activity,but the polysaccharide content and antioxidant activity of the two kinds Anoectochilus are different.The results lay a good foundation for the further study of choosing and cultivating the best origin A.roxburghii.