Carbon material is known from the experience with cardiac valve and tooth implant to have a good biocompatibility. Various types of carbon material have been used in other surgical field ; vitreous carbon fiber reinforced carbon. Graphite is a mineral consisting of the element carbon, crystallizing in the hexagonal system. It is relatively soft and have a high electrical conductivity. In a search for the optimum alloplastic otological biomaterial, we tried to examine graphite. This is the report of long term histologic study of graphite in the middle ear of rat.