Objective:To assess the antioxidant activities of polysaccharide from Acalypha australis L.by different ethanol concentration in vitro.Method:The different part of polysaccharide were precipitated by 30%

45%

60%

75%

80% ethanol.The scavenging rate of the precipitated polysaccharides on（DPPH ·）free radical

superoxide anion radical（O-2 ·）

hydroxyl radicals（· OH） was investigated by ferric reducing method

DPPH · radical assay

O-2 · radical assay and thiobarbituric acid method respectively.The total antioxidantive capacity（T-AOC） and the inhibition on lipid peroxide（LPO） of the precipitated polysaccharides were also been determined.Result:The scavenging activities on the DPPH · reached 73.85%.The results showed that T-AOC was enhanced with the increase of polysaccharide concentration.The antioxidantive especially the scavenging activities on the O-2 · and · OH reached 92.47%

95.89% respectively at 5 g · L-1.Furthermore the scavenging effects were as much as that of vitamin C（VC）.The inhibition of LPO with the polysaccharide precipitated by 75% ethanol was significantly higher than that of any by other ethanol concentrations.Conclusion:the precipitated polysaccharides from A.australis showed strong antioxidant activities.