To investigate the effect of theaflavin-3, 3'-digallate (TFDG) on human lens epithelial cells (HLECs SRA01/04), MTT method was used to establish the oxidative damage model of HLECs induced by high concentration of glucose, at the same time, the changes of cell morphology was observed. The HLECs induced by high glucose were interfered with different concentrations of TFDG (4, 8, 16, 64, 32, 64, 128, 256, 512 μmol/L), the NOS activity and NO level in HLECs were detected by chemical colorimetry and nitric acid reductase method respectively. It was found that HG can inhibit the growth of human lens epithelial cells. The optimal concentration of glucose and the optimal treating time are 50 mmol/L and 24 h. Compared with the model cells, survival rate of modle cells treated with TFDG (16–64 μmol/L) increased (P<0.05), and the NOS activity and NO synthesis in TFDG treated model cells were extremely significantly decreased (P<0.01) in a dose dependent manner. In conclusion, TFDG showed good protect against damage of HLECs induced by high glucose.