To investigate the effect of Longjing tea polyphenol extracts on the oxidative stress,the metabolic enzymes and transporters in C57BL/6J mouse liver.C57BL/6J mice were administrated with three doses Longjing tea polyphenol extracts by gavage.Liver injury was evaluated by pathological sections and the content of ALT and AST in serum.Liver GSH,GSH-Px,SOD and CAT were used to evaluate oxidative stress in mice livers.The relative protein expression level of CYP2E1/1A2/3A11,SULT1A1,UGT1A6,MRP2 and P-gp was evaluated by Western blotting.Results showed that Longjing tea polyphenol extracts could increase the content of GSH-Px and CAT in mice livers to enhance antioxidant defense.And it could induce the protein expression of CYP2E1/3A11,SULT1A1,UGT1A6,MRP2 and inhibit the protein expression of P-gp to adjust metabolism.