Expressions of interleukin-6 (IL-6) and its receptor (gp80、gp130) in 8 patients with Graves' disease (GD) were compared with those in 8 euthyroid patients with nodular goiter or benign thyroid adenoma. The thyroid tissues of GD expressed significantly higher IL-6 mRNA, gp130 mRNA and IL-6 protein than those of the control group, suggesting that activated IL-6/gp130 signal pathway in the thyroid tissue may contribute to the pathogenesis of GD.