Gamgung-tang(GGT) that is included in Gamdu-tang(consists of Glycyrrhizae Radix, black beans) and Gunggui-tang(consists of Angelicae Radix and Cnidii Rhizoma), showed therapeutic effects of autoimmume thyroiditis in the previous reports. GGT was tested for the safety using Rec assay and enzymatic methods. In the Rec assay, Bacillus subtilis H-17$(Rec^+)$ and M-45$(Rec^-)$ strains were used to test DNA damage activity. From the results, there was no DNA damage of GGT. Hepatotoxicity of GGT to female ICR mice was also monitored by the measurements of serum(s)-GOT, s-GPT and LDH activities after oral feeding for 15 days. GGT was not shown any significant changes of s-GOT, s-GPT and LDH activities in mice sera.