Abstract: To explore the effect of tea polyphenols on hyperuricemia (HUA) in mice and its potential mechanism, HUA was induced by intragastric administration of potassium oxonate in mice. HUA mice were treated with150, 300 and 600mg/kg tea polyphenols for 7 days. Uric acid level in serum was tested by phosphotungstic acid assay. Xanthine oxidase activity in serum and liver was determined by chemical colorimetric assay.Results showed that after treatment with 300 and 600mg/kg tea polyphenols, serum level of uric acid markedly reduced by approximate 22% and 29% (both p<0.01) compared with that of model group. Meanwhile, xanthine oxidase activity in serum markedly decreased by approximate 14% (p<0.05) and 21% (p<0.01) , as well as the liver xanthine oxidase activity markedly decreased 16% (p <0.05) and 21% (p <0.01) . In conclusion, tea polyphenols might reduce the level of uric acid in hyperuricemic mice, and the hypouricemic effect of tea polyphenols might be closely associated with the inhibition of xanthine oxidase activity.