Objective: The aim was to study experimentally the effects of Radix Scrophulariae (玄蔘) induced by Sodium levothyroxine. Methods: Sprague-Dawley rats Were separated into four groups. Except for the normal group, the other three were treated with sodium levothyroxine $160{mu}g/kg$ for 5 days. Among the three groups, two (except the control) were treated with Radix Scrophulariae extract 0.5g/kg (HNS 1) or 1.0g/kg (HNS II). $T_3-uptake,;T_3,;T_4$, TSH, total cholesterol, glucose, ALP, AST, ALT, free fatty acid, $eta-lipoprotein$, and change in the serum of rats were measured after medication of solid extract of Radix Scrophulariae. Results: As a result of this study, HNS II showed significant decrease in comparison with the control in the serum $T_3-uptake,;T_3$ ALP and free fatty acid content. HNS I and HNS II showed significant decrease in comparison with the control in the serum of $T_4$ and glucose content. HNS I and HNS II showed significant increase in comparison with the control in the serum of TSH and total cholesterol content. In body weight, HNS I and HNS II showed significant increase in comparison with the control. Conclusion: These results suggest that Radix Scrophulariae is effective to cure hyperthyroidism.