Objective To investigate the supply of iodized salt in non-excessive iodine counties and iodine-free salt in excessive iodine counties at household level in Jiangsu Province so as to provide a basis for the prevention and control of iodine deficiency disorders (IDD) .Methods Objective To investigate the supply of iodized salt in non-excessive iodine counties and iodine-free salt in excessive iodine counties at household level in Jiangsu Province so as to provide a basis for the prevention and control of iodine deficiency disorders (IDD). Methods