Objective To study the necessirity of endocrine treatment for thyroid adenoma after operation. Methods TSH receptors were determined in 100 patient's thyroid adenoma specimens with SP method. The continuous pathologic sections of the thyroid tissues around the tumor were examined to find out that if there was any small focus. The patients were divided into two groups radnomly: Group A, patients received thyroid hormone(TH) treatment after operation; Group B, the patients received no TH treatment after operation. Blood T 3, T 4 and TSH concentration were determined, and the residual thyroid was examined with 131 I scanning and ultrasunography peroidically after operation. Results TSH receptors were presented in all of the thyroid adenomas, and small focus presented in 8% of the patients. Blood T 3, T 4, TSH and residual thyroid were normal in all patients in group A. In group B, Blood T 3, T 4 were below the normal lever in 45(90%), TSH over normal lever in 41(82%),residual thyroid hyperplasia and enlargement were found in 48 patients(96%), and thyroid nodule or tumor in 33(66%). Conclusions TH should be taken in patients with thyroid adenoma after operation to prevent high TSH of serum and tumor replapse, because these patients have the characteristics of muttiple focuses of tumor and postoperative hypothyroidism.