Some experience in the treatment of malignant tumor of the larynx by radiun radiation is briefly reviewed. Harmer-Tsukamoto' s method of radium radiation therapy with placement of radium needles over the thyreoid cartilage suffered from laryngeal cancer, which modified the original fenestration method of Harmer (1932), is used in this experience.The results in 15 cases treated for six years in our clinic are summarized and are found to be contented. Radium therapy of selected cases of early and moderately advanced malignant tumor of the larynx is regarded as the optium method of treatment for functionally satisfactory results of the larynx.