The risk of gene methylation to the various clinical variates, including age, gender, a family history of thyroid disease (such as Graves' disease, goiter, thyroid adenoma and hashimoto thyroiditis (HT); the members include the patient's immediate families within 3 generations), and the level of Tg and TSH, was analyzed using the logistic regression. The gene discussed is TG; the disease is Hashimoto thyroiditis.