Objective： To study the influence of chitosan on proliferation of bladder epithelial cells, so as to discuss its feasibility in treatment of interstitial cystitis. Methods: Bladder epithelial cells were harvested by enzymatic digestion of the epithelium of NewZealand rabbit bladder. The cells were cultured in different concentrations of chitosan（0.3,0.6,1.2,2.4 and 4.8 g/L） for 72 h; untreated cells served as control. The growth and proliferation of cells were observed under microscope. The effects of chitosan on proliferation of cells were studied by NAG assay and cell counting. Results: Immunohistochemistry staining revealed that the cultured cells were epithelial cells. Chitosan (>0.3 g/L) promoted the growth of epithelial cells, and the promoting effect was significantly when the concentration of chitosan was 1.2 g/L (P<0.01).The promoting effects were decreased when the concentrations of chitosan were 2.4 and 4.8 g/L,but were still higher than that of the control group(P<0.01).Conclusion: Chitosan can promote the growth of the bladder epithelial cell in vitro, which might contribute to the treatment of interstitial cystitis