Objective To analyze the survey results of iodine nutritional level among women of childbearing age,pregnant,lactating women and infants before and after the adjustment of iodine concentration in salt of Zibo City,in order to provide a scientific basis for reasonable iodine supplement.Methods The iodine content in the residents' edible salt samples was determined in 2011 and 2015.Four groups of target populations including women of childbearing age,pregnant,lactating women and infants from 7 districts and towns of Zibo were investigated to test their urinary iodine level in 2011 and 2015.The monitoring results of the two years were compared and analyzed.Results A total of 2 100 and 2 160 residents edible salt were monitored in 2011 and 2015,and the median of salt iodine were 30.2 and 22.7 mg/kg,there was statistically significant difference in the constitute of salt iodine level between the two years (x2 =141.90,P ＜ 0.01).A total of 354,402,403,362 urine samples of women of childbearing age,pregnant,lactating women and infants' were detected and the median urinary iodine were 161.80,127.20,138.80,147.10 μg/L in 2011,and 350,706,350 and 352 of the corresponding target population's urine samples were detected and the median urinary iodine were 127.80,129.95,70.20 and 152.35 μg/L in 2015.Conclusions The salt iodine median has reduced and the urinary iodine in childbearing age women and infant is in the appropriate level,while it is insufficient in the pregnant women and lactating women after the adjustment of iodized salt concentration in Zibo.It is necessary to promote health education and instruct pregnant women and lactating women to supplement iodine,additionally,surveillance of the iodine nutrition status of the targeted populations should be strengthened.