Objective To explore the effect and safety of 131I combined Lithium carbonate for the treatment of complex Graves′ diseases. Methods The clinical data of 70 patients with complex Graves′ diseases combined treated with 131I combined Lithium carbonate such as liver dysfunction, leukopenia and arterial fibrillation were retrospective analyzed. The 70 patients with Graves ′diseases treated by 131I only at the same time were severed as controls for treatment effect comparison. Results The patents in combined treatment group got good effects and improved symptoms earlier than those in the control group. Conclusion The combined 131I and lithium carbonate for Graves′ diseases treatment could solve many problems that patients meet during 131I therapy.