Objective：To investigate the iodine nutrition status and thyroid function and their changes in different stages of pregnancy among pregnant Uygur and Han women in Urumqi，China. Methods：The cross-sectional method was used to assess the pregnant women who underwent thyroid function screening in Department of Endocrinology in The People’s Hospital of Xinjiang Autonomous Region from January 2016 to September 2017，and urinary iodine and thyroid function were evaluated. A total of 1268 healthy pregnant women with a single fetus who had complete clinical data were enrolled，among whom 1261 Han，Uygur，Hui，and Kazakh pregnant women were included for further comparison between different ethnic groups. Results：The median urinary iodine of all women was 172.3 μg/L，and of all women，3.79% had severe iodine deficiency，36.99% had iodine deficiency，35.49% had sufficient iodine，18.69% had super sufficient iodine，and 5.05% had excessive iodine. The Han women had the highest level of urinary iodine（182.95 μg/L），and the Uygur women had the lowest level（156.30 μg/L），with a significant difference between the two groups（P=0.01），while there was no significant difference between the other ethnic groups. There was no significant change in urinary iodine during the dif－ferent stages of pregnancy in each ethnic group. There was a significant difference between the Han and Uygur groups in serum thy－roid stimulating hormone（TSH） level in the first，second，and third trimesters（first trimester：3.57±2.93 vs. 5.13±7.12，P <0.001；second trimester：2.92±1.68 vs. 3.82±4.52，P=0.008；third trimester：2.70±1.31 vs. 3.62±1.85，P <0.001）. There was no clear cor－relation between urinary iodine and TSH. Conclusion：There is good iodine nutrition status in pregnant women in Urumqi，but 40.77% of these women have iodine deficiency，and Uygur women have more serious iodine deficiency. Han women have a lower TSH level than Uygur women during each stage of pregnancy，which is dif－ferent from the results of the local natural population during the same period of time. There is no correlation between urinary iodine and TSH.