Purpose To investigate apoptosis in vitrectomy specimens of proliferative vitreoretinopathy. Methods Vitrectomy specimens from 60 cases of different classes of proliferative vitreore tinopathy were studied by TdT-mediated dUTP nick end labelling(TUNEL)method. Results The characteristic change of apoptosis was observed in all vitrectomy specimens.The amount of apoptotic non-pigmentary cell is gradually decreasing along with the development of proliferative vitreoretinopathy,and apoptotic pigmentary cells are observed. Conclusion There are different kinds of apoptosis cell in vitrectomy specimens of proliferative vitreoretinopathy.It is suggested that apoptosis might be one of the important mechanisms of regulating the degree in proliferative vitreoretinopathy. (Chin J Ocul Fundus Dis,1999,15:81-83)