Reticulum cell sarcoma of the E.N.T. fields is truly a very rare tumor and this malignant neoplasm has been frequently observed and intensive studies are carried out by many workers. But they are highly malignant tumors histopathologically and clinically and grow more rapidly than lymphosarcoma. This neoplasm is derived from the reticulum cell, which is identical with the histocyte and the large wondering mononuclear macrophage. For ten years up to date, from 1968 to 1977, seven cases, two female and five male patients of localized reticulum cell sarcoma(Reticulum cell sarcoma of the palatine tonsil ; Five cases, Reticulum cell sarcoma of the nasopharynx ; Two cases) have been experienced at outpatient clinic of our department. This is the report of the cases with review of the literature.