Abstract: Objective Tocompare the expression and its significance of glutathione peroxidase(GSH-Px)and glu tathione-S-transferase(GST-Pi)in hepatictissue in oral drinking arsenicexposed mice.Methods 60 mice were divided intocontrol group,sodium arsenite group and sodium arsenate group atrandom.The mice were sacrificed after 10 month for the liverfunction,total arsenicdetection and patholog icexamination.Extractthe total RNA of hepatictissue and detectits density and purity,detectthe expression of GSH-Pxand GST-Pi mRNA with real time fluorescence quantitative PCR and the resultwas controlled with 18s.Results Arsenica ccumulation in sodium arsenite group(3 992±250)ng/g tissue was hig herthan thatof sodium arsenite group 2603±357ng/gtissue,P<0.05.Pathologicexaminations showed thatthere were notable livercell necrosis and regeneration.Serum AL T6.46±13.85,U/L.AST(510.86±59.0)I U/L.G1b(26.94±3.73)g/L in sedium arsenite group was higher than thatof the normal group,while the expression of GST-Pi mRNA(163.3±11.6)was lower(P<0.05).Conclusion There were relationship between hepaticinjury and arsenicaccumulation.Oxidative stress may be the one of sig nificanteffects in the process of hepaticinjury caused by oral drinking arsenicexposure in mice.