【Abstract】Objective To study the relation between iodine and experimental autoimmune thyroiditis(EAT). Methods Establishment of animal model was performed with iodine and thyroglobulin(TG).The rats were randomly divided into 5 groups: normal control group(NC), low iodine group (LI,500 μg/L), high iodine group(HI,500 mg/L), TG+Freund adjuvant group(TG) and TG+Freund adjuvant+HI group(TG+HI). The rats in TG group and TG+HI group were rejected hypodermically with TG emulsified by complete Freund adjuvant, and strengthen immunity was conducted with TG emulsified by incomplete Freund adjuvant on 15 days. After that, strengthen immunity was done weekly till the end of the experiment. Serum TGAb and TPOAb were measured by radioimmunoassay. Observation of the pathological changes of thyroid gland was also done. Results Thyroid follicular destruction and lymphocytic infiltration in the TG+HI group (3.83±1.72) and HI group (3.00±0.89) were significantly higher than that of the NC group(0.67±0.82)，P＜0.05. The results of the TG group were higher compared with the NC group, but there were no significant differences between them（Pgt;0.05）. The levels of TGAb in the TG+HI (4.990±1.505)，HI (3.589±1.240) and TG group (4.883±1.198) were significant higher than those of the NC group (0.642±0.454) and the LI group (0.707±0.240)，P＜0.01. The levels of TPOAb in TG+HI group (1.475±0.523) and TG group (1.316±0.606) were significantly higher than those of the NC group (0.365±0.196) and the LI group（P＜0.01）. Serum TGAb and TPOAb levels were positively correlated with the histological grades of lymphocytic thyroiditis(r=0.9,P＜0.05）. Conclusion Excessive iodine intake may induce the occurrence of EAT. The induction of EAT with excessive iodine and TG may be more efficient.