Abstract: Objective To analyze distribution characteristics of iodine nutrition and its influencing factors among the children in Hainan province.Methods Across section study was conducted in the area with historical iodine deficiency(AHID)and the area withoutio dine deficiency(NID).Factors affecting iodine nutrition status was analyzd based on the results of urinary iodine de tection and thyroid examinatiion of 2699 children bewteen 8 and 10 years old.Results The iodized salt cover rate,the median of urinary iodine,rate of goiter among the children in AHID were 92.5%,196.2μg/L and 6.0%,respectively,higher than those in the children of NID(48.5%,91.9μg/L,3.5%).The iodized salt cover rates in the children with different housing geographical position,age and sex in AHID was between 28.4%-46.7% and higher than those of in NID.The urinary iodine medians for children in AH ID were between 62.5-145.9μg/L and higher than those of children in NID.In AHID the proportions of clildren with urinaryiod ine less than 50μg/L were between 14.1% and 20.0% and that of less than 100 μg/L were between 27μ8% and 39μ9%,both lower than that of the children in NID.Multi factor logistic regression analysis showed positive correlations betweeniodine nutrition status and living in AHID and use of iodized salt(OR>1,P<0.001).Conclusion Saltio dine is the important measure to improveiod ine nutrition.Iodine nutrition status in children in area swith historical iodine deficiency is appropriate and the iodine nutrition status among the children in the areas without iodine dificieney,especially in plains should be concerned.