There have been several studie3s using experimental animal models to clarify the characteristics of human cholesteatoma. Among the methods, ligation of the external auditory canal in the gerbil was realized to be easy to induce the cholesteatoma and presented many similarities with human cholesteatoma. In this study, we could induce the aural cholesteatoma by ligation of the external auditory canal in gerbils. The stages of cholesteatoma were closely related to the duration of ligation and significant bony destruction occurred with inflammation.