Objective To investigate the change of prevalence of autoimmune thyroiditis in Guiyang city after adjustment of salt iodine content,and to study the link between the level of iodine intake and the development of autoimmune thyroiditis.Methods With cluster sampling method,a cross-sectional study was conducted among adults aged20 years old or above in Guiyang in 2009(before adjust- Objective To investigate the change of prevalence of autoimmune thyroiditis in Guiyang city after adjustment of salt iodine content, and to study the link between the level of iodine intake and the development of autoimmune thyroiditis. Methods with cluster sampling method, a cross-sectional study was activities among adults aged20 years old or above in Guiyang in 2009 (before adjust-