Abstract: Objective To investigate the clinical curative effects of ¹³¹I therapy combined with low-dose lithium carbonate for Graves disease.Methods Patients with Graves disease took lithium carbonate (250mg, once per day) orally for 5 weeks. Then they were treated with ¹³¹I (doses=3.15 MBq(80 uCi)/g, based on 60%~70% of the thyroid size). We kept track from 6 to 24 months (averaging 14 months) and classified the results into three:cured, improved or no effect.Results After a single cycle of ¹³¹I therapy combined with low-dose lithium carbonate, 106 patients with Graves disease were cured, 28 were improved and 8 saw no effects, respectively 74.6%,19.7% and 5.6% among the 142 patients. We then treated 23 of them with another ¹³¹I therapy (without lithium carbonate). 10 of such were cured (43.5%), 8 were improved (34.8%) and the other 5 saw no effects. Among all patients, hypothyroidism was observed from 25 (17.6%), 6 months after the first ¹³¹I therapy.Conclusions Notable curative results were observed from ¹³¹I therapy combined with low-dose lithium carbonate for Graves disease. Moreover, the dosage of ¹³¹I was therefore decreased, which also lowered the toxicity response.