Middle ear neoplasm with imperforate drum is seldom seen due to the difficulty of the early detection. Two operated cases of such condition are dealt with in this paper. The first case is the adenoid cystic carcinoma of 17 years old male and the second is the glomus jugulare tumor of 59 years old male. The symptoms of these two cases are full feeling, tinnitus and hearing loss of the conductive type in the affected ear, which are not particular only to this condition. Each case showed 3 years' and 2 years' survival without recurrence after the operation respectively. The early detection of the middle ear neoplasm leads to the good result. So as to confirm this condition at an early stage of clinical course it seems very important for the otologist to keep in mind the presence of mass lesion of the middle ear and its clinical features. It is authors' opinion that the drum is natural anatomical barrier in this neoplastic condition of the middle ear. From this view point the clinical stage of the middle ear neoplasm is classified into three stages, which is described in this paper.