One hundred and six cases of brain tumors were treated at the Yonsei Cancer Center form January 1972 to August 1978 by Co-60 teletheraphy unit. We analyses their clinical findings, histopathological findings, treatment and results. In those cases which computerized tomography had been used before and after radiation theraphy, changes in tumor size and the presence of edema or necrosis following treatment was evaluated. 1. Among 106 cases, 90 cases were primary brain tumors and 16 cases were metastatic brain tumors. Pituitary tumors (38), glioma(34) and pinealoma (10) composed of most of primary brain tumors, 2. Post treatment follow-up was possible in 38 cases more than 1 years. Four among 11 cases of glioma expired and survivors had considerable neurologicla symptoms except 2 cases. Sixty five percent which post treatment follow-up was possible, showed remarkable good response. 3. Findings of C-T scan after radiation treatment were compatible with results of clinical findings and post treatment follow-up. It showed complete regression of tumor mass in one cases of pinealoma and medullobulastroma. One case of pituitary tumor show almost complete regression of tumor mass. It also showed large lesion in cases of glioblastoma multiforme and cystic astrocytoma.