Objective : Hypothyroidism is a common disease of the endocrinal system. characterized by fatigue, cold intolerance, bradycardia, and so on. Clinically, Levothyroxine(L-T4) has been usually used for replacement therapy, but it often has side effects. so many hypothyroidism patients wants oriental medical therapy. Zingiberis rhizoma, traditionally has been used in treatment of coldness, fatigue, and bradycardia. In this study. I investigated the therapeutic effects of Zingiberis rhizoma on PTU induced hypothyroidism in rats. Methods : I used two-month-old rats administered PTU and induced with hypothyroidism. After 2 weeks. Zingiberis rhizoma and thyroxine were daily administered, respectively. Body weights was measured every weeks. After 4 weeks, blood samples were taken and analyzed biochemically and T4 and TSH were measured by ELISA kits. Results : In comparison with normal groups, control groups showed hypothyroidism with low T4 and high TSH level. In Zingibris rhizoma administration groups were observed T4 level elevation, this elevation was dependent on the dose of Zingibris rhizoma. Between experimental groups and control groups, there was no difference in TSH level, statistically. Changes of biochemistry were not observed in any experimental groups. Conclusions : These findings suggest that Zingiberis rhizoma makes thyroid cells producing thyroid hormones. There is also a non-toxic effect on the cardiovascular system, liver and kidney function. So, Zingiberis rhizoma should be an effective agents for treating hypothyroidism.