The prevalence of olfactory dysfunction increases significantly in recent years. More than 35 patients with COVID-19 have sequelae of olfactory dysfunction after recovery. However, there are no effective treatments for sensorineural olfactory dysfunction to date. This is the first report demonstrates that chitosan can promote differentiation of olfactory receptor neuronsregenerate olfactory neuroepithelium. Further intranasal administration of chitosan will be developed for treating olfactory dysfunction.