Abstract: ObjectiveTo probe the main influence factors of changes of iodine nutrition and its morning sickness in early stage of pregnant women.MethodsTo collect questionnaires and morning urine in early stage of pregnant women who lived in the center of city for more than three years,and use method of GB/T-1998 to measure urine iodine content.ResultsThe urine iodine content of early stage of pregnant women(G)(146.5μg/L)was quite obv iously lower than non-pregnant women of the same age and middle-stage pregnant women(293.9μg/L and 182.6μg/L P_av<0.01).There were stat istical significant differences between the urine iodine content of early-stage pregenant women who had morning sickness(113.0μg/L and urine iodine content<100μg/L,29.8%)and non-pregnant women(221.8μg/L and 2.7% P_av<0.01).ConclusionThere was a straight relation between decrease of urine iodine content in the last-stage of early pregnant women and its morning sickness.Therefore it cannot satisfy the needs of early-stage of pregnant women,to depend on salt to replenish iodine.