Objectives : The aim was to study experimentally the effects of KABHANG-BANG(갑항방) on the hyperthyroidism of rats induced by sodium levothyroxine. Methods : Spargue-Dawley rats were separated into four groups. Except normal group, the other three groups were treated with sodium levothyroxine $32{mu}g$/200g/days for 5 days by oral administration. Among the three groups, two except one(as control) were treated KHB extract 225mg/200g/days(sample A), 450mg/200g/days(sample B) for 3 days separately. T3-uptake, T3, T4, r-TSH, total cholesterol, total protein change in the Serum of rats were measured after medication of solid extract of KHB. Results : As a result of this study, in the serum T3 and T4 level were decreased in sample A and B compared to controls. The serum r-TSH, total cholesterol and total protein were increase in sample A and B compared to controls. In the serum T3-uptake content, Smple B showed significant decrease in comparison with control group, but Sample A did not show significant decrease. Conclusion : According to the above results, it is suggested that KHB is effective to cure hyperthyroidism.