Objective:To introduce the free radical scavenging and anti-lipoperoxidative activities of gallic acid in vitro and to obtain the experimental data of antioxidant activities.Methods:Using spectrophotometry

the effect of gallic acid in scavenging free radical ·OH

free radical ·2

2-Diphenyl-1-picrylhydrazyl and H2O2 were determined.The antilipoperoxidative effect of gallic acid was also evaluated by spectrophotometry.The scanvenging level of NO was tested by Griess.The experiments were studied respectively and compared with vitamin c（Vc）.Results: Gallic acid in the suitable concentration 5

5

0 μg/ml could scavenge 2

2-Diphenyl-1-picrylhydrazyl by（20.65±2.67）%

87.98±4.12

% in dose dependent manner.The scavenging capability of gallic acid for 2

1-Diphenyl-1-picrylhydrazyl was significantly higher than that of vitamin c.Gallic acid in the suitable concentration 50

4

00 μg/ml could scavenge NO by（10.45±3.45）%

40.43±2.76

%

which was slightly lower than vitamin c.Gallic acid in the suitable concentration 50

4

00 μg/ml could scavenge hydroxylion by（47.32±3.26）%

67.25±2.99

%

which was significantly higher than vitamin c.The capability of gallic acid for scavenging against H2O2 in vitro was weak.Gallic acid in various concentrations 50

4

00 μg/ml could inhibit lipid peroxidation effectively and the rate of inhibition was（48.65±5.21）%

80.03±5.64

%

which was significantly higher than that of vitamin c.Conclusion:There is powerful scavenging effect of gallic acid against different free radicals in vitro.This might be one of the reasons for its antioxidant activities in vivo.