To assess the clinical value of treatment with 131I for brain metastases from differentiated thyroid cancer (DTC), we have observed 8 cases of brain metastases from DTC who received follow-up after 131I therapy (2male, 6 female, aged 12～65 years). The results of 131I therapy were evaluated with clinical presentation, imaging scan and survival analysis. The main results are as follows. (1) All cases had been survival for 2～35 years in follow-up. (2)A space-occupying lesion in right cerebellum was reduced after taking 20.65 GBq and disappeared after 23.61 GBq,demonstrated by computed tomography. (3) The sequences and doses of 131I therapy were clearly decreased for the cases with total thyroidectomy in comparison with those with semithyroidectomy (p＜0.01). (4) The brain metastases with lung and/or bone metastasis from DTC were 75% (6/8) and it was difficult to cure these metastases at the same time. It is concluded that the postoperative treatment of 131I for brain metastases from DTC after undergoing thyroidectomy may improve clinical symptoms and life quality, reduce lesions, and prolong survival.