During a last decade many data have been accumulated, which indicated an important role of cytokines in the pathogenesis of Cholesteatoma. The bone absorption was already clarified to be under regulation of IL-1 and TNF-alpha by in vitro model. In this paper, effects of several cytokines on the growth of keratinocytes of eardrum were examined in vitro to determine whether Cholesteatoma is a cytokine disease or not. Whole eardrums was removed with a part of external ear canal and ossicles from male 5 weeks old CBA/S1c mice and were incubated in the KBM culture medium with or without IL-1alpha, IL-1beta, IL-6, IFN-gamma, LPS and TNF-alpha. The eardrum preserved its structure up to 7days in the culture medium, and the pars flaccida of the eardrum formed a retraction pocket in the medium with IL-1beta, IFN-gamma, TNF-alpha, LPS, or IL-6.