Objective: To investigate the influence of excessive iodine on the thyrocytes autophagy and apoptosis and its significance in hashimotos thyroiditis.Methods: Immunohistochemical staining was used to detect the clinical patients thyroid tissue with thyroiditis autophagy and apoptosis related proteins.Nthyori-3-1 cells were co-cultured with different concentrations of potassium iodide (KI) after 12 h.By means of western blot technology to detect autophagy related protein roTOR (mammalian target of rapamycin), and LC3 (microtubule associated protein light chain 3) expression levels.Respectively using flow cytometry, MTT (3-4, 5-dimethylthiazol-2-yl-2, 5-diphenyl-tetrazolium bromide) assay to measure apoptosis rate and proliferation of cells.