Abstract: Objective: To study the changes of serum thyroglobulin antibody( TGAb),thyroid peroxidase antibody( TpoAb) and thyroid hormone receptor antibody( TRAb) levels in Hashimoto's thyroiditis( HT) and Graves disease( GD),and evaluate their clinical values. Methods: Two hundred and forty cases of hyperthyroidism were selected,including 112 cases of HT in group Ⅰ,66 cases of GD in group Ⅱ,62 cases of non autoimmune hyperthyroidism in group Ⅲ,and 80 healthy persons in group Ⅳ. Serum TGAb,TpoAb and TRAb levels were detected by electrochemiluminescence immunoassay in four groups. Results: The serum TGAb,TpoAb and TRAb levels from the patients in Group Ⅰ were significantly higher than in group Ⅱ,Ⅲ and Ⅳ( P 0. 01); the serum TGAb,TpoAb and TRAb levels in group Ⅱ were also significantly higher than those in group Ⅲ and Ⅳ( P 0. 01). In group Ⅰ,the positive rate of TGAb was 90. 17%,the positive rate of TpoAb was 100. 00%,the positive rate of TRAb was 6. 25%; in group Ⅱ,the positive rate of TGAb was 30. 30%,the positive rate of TpoAb was 70. 21%,the positive rate of TRAb was 90. 90%. Conclusions: Detection of serum TGAb, TpoAb,TRAb level plays an important role in the diagnosis and differential diagnosis of HT and GD in autoimmune thyroid disease,the elevation of TRAb plays special diagnostic value for GD.