Antithyroid drugs are widely used in treatment of Graves' disease (GD), but after therapy withdrawal, relapse rate is very high. The aim this trail is to evaluate the effects of intrathyroid injection of dexamethasone combined with antithyroid drugs on patients with newly diagnosed GD.

The morbility of GD is nearly 0.5% and the underlying cause of 50 to 80% of cases of hyperthyroidism.Recently,anti-thyroid drugs are still the main therapy for Graves'hyperthyroidism in a lot of districts, but the relapse rate is very high (51~68%) after withdrawal of anti-thyroid treatment.In order to reduce the relapse rate, some studies tried to prescribe replacement thyroxine, either with the anti-thyroid drug treatment, or after this was completed, but there is no clear evidence in favour of giving thyroid hormone supplementation following the initial treatment of Graves' thyrotoxicosis with anti-thyroid medication. Therefore, the optimal medical therapy for Graves' hyperthyroidism remains a subject of debate.

It is well known that glucocorticoids have anti-inflammatory, immunomodulation and immunosuppression effects and they has long been used to treat GO, and is one of the most effective medicine ,it can decrease some cytokines and reduce inflammatory status ,and improve some thyroid specific antibody, like as thyrotropin receptor antibodies (TRAb), antithyroperoxidase antibodies (TPOAb) and antithyroglobulin antibodies (TGAb).These studies suggested that glucocorticoids might affect autoimmune process and have some benefit effects on GD. Moreover glucocorticoids have been used to treat GD in several early reports, in which serum free triiodothyronine (FT3) and thyroxine (FT4) or total T3(TT3) and TT4 levels decreased after 8 days or three weeks treatment with glucocorticoids . But in those studies, the number of selected patients is small, and the duration of the therapy is relatively short, so that might not confirm the effects of glucocorticoids on GD.

Inclusion Criteria:

• Newly diagnosed of Graves' Disease

Exclusion Criteria:

• Pregnancy
• Allergy to ATD, Alanine aminotransferase (ALT) or asparate aminotransferase (AST) above 2 times of upper normal range
• Non-compliance because of psychiatric or other serious diseases, or unwillingness to participate in the study.