431 patients with tumor of head and neck were treated by radiation at Yonsei Cancer Center. 145 patients of431 patients were available for follow-up examination. 145 cases were reviewed in respect of method of radiationtherapy, incidence of diseases, sex, age histologic type and effect of radiation therapy in the view of prognosis.1. The most common lesion among the tumor of head and neck was laryngeal cancer 38.6%(56/145) and next wasmaxilary cancer 20.7(30/145), nasopharyngeal cancer 13.8(20/145), tongue cancer 9.6%(14/145), tonsillar tumor6.9%(10/145), parotid tumor 5.5%(18/145) and the last was thyroid gland tumor 4.8(7/145) 2. Sex incidence showsmoer common in male in laryngeal, maxillary, nasopharynx, tongue, tonsil, and parotid gland tumor, however morecommon in female in thyroid cancer. 3. The peak age incidence was 5th and 6th decade in all head and neck tumor.4. In histologic type, epidermoid cell cancer was the most common type of larynx, maxillary, nasopharynx, tongueand tonsillar lesion and mucoepidermoid cancer is most common in the parotid gland tumor. 5. Average survivalmonths after radiation therapy was 22.4 months in laryngeal cancer, 18.9 months in maxillary cancer, 106 months innasopharyngeal tumor, 20.5 months in tongue cancer, 21.4 months in tonsillar cancer, 26 months in parotid glandtumor and 13.6 months in the thyroid gland tumor. 6. Postradiation complication were minor degree of dry mouth,taste loss andskin discoloration,but major complication such as necrosis of soft tissue and bone or transversemyelitis of spinal cord was not developed.