The author studied hearing acuity, findings of nsopharyngoscopic examinations and changes in the patency of the Eustachian tube in the 277 ears of the children with tubal stenosis, ranging in age from 5 to 15 years, who had received various tseatments without success in our Better Hearing Clinic, Departmment of Oto-Rhino-Laryngology, Okayama University Medical School and who has been finally submitted to the radium irradiation therapy 1) As for the method of radium irradiation, a piece of radium needle containing 5.5 mg. radium is put in a brass holder 1 mm. thick and it is inserted up to the orifice of the Eustachian tube through the nose and fixed in the nasopharyngeal cavity. As for the amount of irradiation, an individual case receives 3 to 4 times of 33 mg. hour of irradiatiou for six hours at a time at the interval of seven days, which is considered as a round of teeatment. Usually only one round of such treatment has been given, but in some cases two or three rounds have been administered with 2 to 5 months' interval between the rounds. 2) Out of the 216 ears examined by an an audiometer 144 ears (66.7%) have recovered to the normal hearing; and the 61 ears given infant speech tests have likewise yielded approximately the same results. 3) In order to obtain a better result in the radium treatment, it is necessary to give first such treatments as the treatment for the fluid in the middle-ear cavity, adenoid, or sinusitis. 4) Out of 156 ears, 104 (60,6%) improed by the irradiation treatment. In these 104 cases the majority of them showed granular change of the Eustachian orifice or residual adenoid in the nasopharynx, and furthermore, these types were the ones to whom the irradiation treatment proved to be most effective. 5) As for the patency of the Eustachian tube, 63 ears (60%) of 105 cases with severe stenosis showed improvement after the irradiation, while 38 ears (80%) of 47 cases with mild stenosis improved, 6) As the relapse is apt to occur even more than one year after the treatment, it is necessary to carry on the periodical follow-up examinations.