Objective:To investigate the iodine nutrition status of key populations in Tengzhou City, Shandong Province, and provide a scientific basis for prevention and control of iodine deficiency disorders in the future.Methods:From 2017 to 2021, a stratified cluster sampling method was adopted, 21 iodine deficiency disorders towns (streets) in Tengzhou City were divided into 5 sampling areas based on east, west, south, north, and center, with 1 town (street) selected as the monitoring site from each area every year; 40-non boarding students aged 8 - 10 (half male and half famale, age balanced) from one primary school and 20 pregnant women (early, middle, late pregnancy balanced) were selected from each town (street), and their household salt and urine samples were collected for test of salt iodine and urine iodine contents.Results:A total of 1 506 household salt samples were collected, the median salt iodine was 24.29 mg/kg, the coverage rate of iodized salt was 96.55% (1 454/ 1 506), the qualified rate of iodized salt was 93.40% (1 358/1 454), and the consumption rate of qualified iodized salt was 90.17% (1 358/1 506). There were statistically significant differences in the median salt iodine and coverage rate of iodized salt among different years ( H = 119.61, P < 0.001; χ 2 = 14.53, P = 0.006). A total of 1 000 urine samples were collected from children aged 8 - 10, with a median urine iodine of 182.20 μg/L. The differences in urine iodine between different years, genders, ages, and urban and rural children were statistically significant ( H = 38.18, 13.96, 49.30, 8.34, P < 0.05). A total of 499 urine samples were collected from pregnant women, with a median urine iodine of 152.40 μg/L. There were statistically significant differences in the median urine iodine of pregnant women in different years ( H = 20.09, P < 0.001). Conclusions:The iodine nutrition of children and pregnant women in Tengzhou City is at an appropriate level. However, the consumption rate of qualified salt iodine and the urine iodine level of pregnant women are at the lower limit of the standard, and there are fluctuations, posing a risk of iodine deficiency. Relevant departments should focus on strengthening the management of iodized salt, monitoring iodine deficiency among key populations, and providing health education to achieve scientific iodine supplementation and sustained stable iodine nutrition suitability.