In order to investigate the role of Caspase-3 and Bax in the pathogenesis of lichen planus, immunohistochemistry was used to detect the expression of Caspase-3 and Bax in skin lesions of the patients with lichen planus and skin tissues of normal subjects. The results showed that positive rate of Caspase-3 and Bax expression in lichen planus were significantly higher than that in normal skins (both P<0.05). Meanwhile, there was a obvious correlation between the increase of Caspase-3 and that of Bax in lichen planus. The expression of Caspase-3 and Bax might play an important role in the development of lichen planus.