Purpose: To investigate whether normal and senescent lens epithelial cells have different defense abilities to apoptotic induction factor in vitro.Methods: Rabbit lens epithelial cells were cultured, passed. When reaching confluence, cells from the first and seventh passage were stained by x-gal staining to detect cell senescence. Cell apoptosis was detected by TUNEL(Roche).10μmol/L camptothecin was used to induce cell apoptosis from the lens epithelial cells of the first and seventh passage to distinguish different sensitivities to apoptotic induction factor between normal and senescent cells.Results: The senescent cells (41.17% ± 5.24% ) were detected in the lens epithelial cell culture of the seventh passage, which are higher than those of the first passage (0.98% ±0. 39% ). There was no apoptotic cell detected in the cell cultures undisturbed. Exposure of the first passage cells to camptothecin resulted in death of approximately 23.87% ± 3.45% of the cells during a 36 hour exposure period. In contrast, significantly more lens epithelial cells died through the apoptosis (38.29% ±4. 01% ) from the seventh passage.Conclusion: Senescent cells increased with cell passage. Senescence lens epithelial cells do not undergo apoptosis if they were not disturbed. But the vulnerabilities to apoptotic induction between health and senescence cells were different.