Abstract:The polysaccharide of Lycopus lucidus Turcz.harvested form two sites and three periods were obtained through hot water extraction and ethanol precipitation.The polysaccharide content was determined by Folin-phenol method.The antioxidant activity of L.lucidus Turcz.polysaccharide was evaluated by DPPH radical scavenging activity，FRAP and nitrite scavenging effect.The results showed that the polysaccharide yield of L.lucidus Turcz.was in range of 28.40 g/100 g to 42.20 g/100 g，which was first increased and then decreased with the harvest time delayed.The polysaccharide content of L.lucidus Turcz.was in range of 16.95 g/100 g DW to 31.61 g/100 g DW，and their changes were various in the period of harvest.The polysaccharide of L.lucidus Turcz.possesed higher antioxidant activity.The DPPH radical scavenging capacity，FRAP value and nitrite scavenging effect ranged from 68.34%to 76.38%，122.75μmol Fe（II）/g to 239.00 μmol Fe（II）/g and 58.82% to 87.37%，respectively.In the same antioxidant system，the antioxidant activity of L.lucidus Turcz.polysaccharide obtained from different sites were discrepant in the period of harvest.The antioxidant activity of L.lucidus Turcz.polysaccharide obtained from different sites were varoius in different antioxidant system in the period of harvest.