Abstract: Objective: To study the effect of p27 expression on glomerular cell proliferation in experimental glomerulosclerosis. Methods:The rat glomerulosclerosis model was induced by Adriamycin. Proliferation was determined by semi-quantitative RT-PCR assay and immunohistochemistry on proliferation cell nuclear antigen（PCNA）. The glomerular cell p27 protein expression was evaluated by immunohistochemistry at th study point. Results:Semi-quantitative RT-PCR revealed increased PCNA mRNA expression in the experimental glomeruli, whereas no PCNA mRNA expressed in the control glomeruli, which coincided with the results of proliferation indices. p27 decreased progressively There was significantly negative correlation between p27 and PCNA mRNA expression（r=0.8043,P＜0.05）. Conclusions:Glomerular cell proliferation increased progressively with the development of glomerulosclerosis, the decreased p27 expression is likely to participate in the regulation of glomeular cell proliferation.