Objective To study the effect of chitosan on the growth of the in vitro cultured retinal nerve cells. Methods The retinal nerve cells of SD baby rats were cultured in vitro. The effects of chitosan at 0.065%,1.25%,2.5%,5%,10%,15% on the growth of the retinal nerve cells were measured by MTT method. The blank control group was created. Results 1.25%,2.5%,5%,and 10% chitosan could obviously promote the growth of retinal nerve cells,and 10% chitosan was the optimal concentration for the growth of nerve cells. Conclusion Chitosan can effectively promote the growth of retinal nerve cells,and it is necessary to undertake the further study of Chitosan.