Abstract: Objective To observe oxidative damage of human bronchial epithelial cells (BEAS-2B) induced by uranium-mineral dust(UD) and protective effect of tea polyphenols(TPs).Methods The measurement of extracellular superoxide anions(O₂·^-) was based on the reduction of ferricy to chrome C.The quantitation of extracellular hydrogen peroxides(H₂O₂) was based on horseradish peroxidase-dependent oxidation of phenol red.The determination of extracellular hydroxyl radicals(·OH) was based on the decoloration of safranine T.E thidium bromide, 2, 7'-dichlorofluorescein, and fluorescent products of membrane-permeable dyes-hydroethine and 2, 7'-dichloroflurescein diacetate were used to monitor in tracellular production of O₂^· and H₂O₂, respectively.The conten to flactate dehydrogenase was measured by AUTOLAB.Cytokinesis-block(CB) assay was used to detect the mutation frequency of hyloxan thine-guanice phosphoribosyl tranferase (HPPT).Results The reactive oxygen species (ROS) production including H₂O₂, O₂·^-, and ·OH induced by UD increased remarkably in BEAS-2B cells.Superoxide anion was 10.48±0.75μmol/L in high dose group and 9.31±0.71 in TPs group.The mutation frequency (MF) of HPRT gene increased.MF of HPRT gene was 1.092‰ in high dose group and 0.925‰ in TPs group.The changes could be inhibited effectively by 250mg/L of TPs.Conclusion UD causes oxidative damage in BEAS-2B cells.Through removing active oxygen, TPs can inhibit oxidative damage of UD.It can provide an effective measure to the protection of UD.