1) The 77 patients wtih thyroid Ca. diagnosed with pathological findings from 1970 through 1976 are analyzedin histological type, metastatic involvement and preoperative thyroid scan and function test. Among 58 patientswith thyroid Ca. 38 patients were performed by thyroid surgery only and 11 were teated with external irradiationafter thyroid surgery and 2 with external irradiation only, 6 patients were treated with radioiodine after thyroidsurgery and 1 with radioiodine only. 2) Among 11 post-thyroidectomy patients treated with external irradiation, 9have had local control after therapeutic dosage of irradiation and 1 with local recurrence and 1 withpostoperative palpable necknode has had diappearance of a previous node after irradiation. 2 inoperative patientswith Anaplastic types expired within 4 months after therapeutic dosage of external irradiation. 3) Among 5inoperative patients treated with radiodine, 2 with recurrent Ca. and Rib metastasis showed improvement by x-rayor clinical finding after radioiodine treatment of 30 mci for each patient, one with lung metastasis showedmoderate improvement of metastatic lesion by x-ray after radioiodine therapy of 40 mci and 2 with multiple bonemetastasis revealed improvement by x-ray or clinical finding after I-131 administration of 60, 120mci for eachpatients. 2 postthyroidectomy patient with neck node metastasis by operative and pathological findings revealedlocal control after I-131 therapy of 5, 30 mci for each one.