Abstract: Radioiodine ablation of thyroid remnants after surgery is an important part of the treatment of differentiated thyroid carcinoma.The effect of ablation therapy is affected by many factors, such as the administration dose of radioiodine, mode of operation, amount of thyroid remnants, the serum level of thyroidstimulating hormone and thyroglobulin, whether lymph nodes or distant metastasis are existed, the period of time between the ablation treatment and the operation and so on.Relative high dose of radioiodine, total or near-total thyroidectomy, high level of thyroid-stimulating hormone, ablation treatment onset after surgery without delay would contributed to the success of thyroid ablation.If the patient's thyroglobulin levels are high or metastasis foci are existed, the dose of radioiodine should increase to some extent.While patient's gender, age and pathology are unrelated to the treating effect.