Abstract: Objective To observe the clinical effect of bicyclol on liver injury induced by hyperthyroidism. Methods Total of 97 patients with liver injury induced by hyperthyroidism were randomly divided into two groups: treatment group (49 cases) and control group (49 cases). Both groups received oral anti-thyroid drug tapazole (15 mg daily). Patients in treatment group were orally treated with bicyclol (75 mg daily), and incontrol group received diammonium glycyrrhizinate capsules (450 mg daily) orally. The treatment course for both groups was 4 weeks. Curative effect after the treatment was observed. Results After treatment for 4 weeks, liver function in both groups were improved, which were more significant in treatment group compared with the control group (P ＜ 0.05). For the comprehensive effect, the rate of marked effect and total effect of treatment group were superior to that of the control group with statistical significance (P ＜ 0.01). No drug-related adverse events detected during the treatment. Conclusions Bicyclol is effective and reliable in the treatment of liver injury induced by hyperthyroid.