Abstract: 1 228 hyperthyroidism patients treated with two doses of 131I 3.7~4.4 MBq/g and 2.59~3.96 MBq/g are abserved and the results are compared. The results indicate that the administered dose is larger the treating rate is higher, and hypothyroidation occurs frequently; while the dose is lower, the treating rate and hypothyroidation is also getting lower. So, there are some other factors of the indication selection, the estimation of thyroidism size, individual sensitivety and the hyperthroidism nature history and so on should be considered in the hyperthroidism therapy for improving the therapeutic effect.