〔Abstract〕 Objective To analyze the difference of urinary iodine level in Hashimoto thyroiditis(HT) patients, and to explore the possible relationship between urinary iodine level and HT under different iodine nutritional status, so as to provide some references for reasonable iodine intake in HT patients. Methods A total of 101 hospitalized HT patients were selected as HT group and divided into 3 groups according to thyroid function: HT group with hyperthyroidism(41 cases). There were 25 cases in HT group with normal thyroid function. There were 35 cases in HT combined with hypothyroidism group. In addition, 30 healthy subjects were selected as control group. Serum levels of thyroid stimulating hormone(TSH), triiodothyronine(T3), thyroxine(T4), thyroid peroxidase antibody(TPOAb) and thyroglobulin antibody(ATG) were detected by chemiluminescence assay. The size and morphological structure of thyroid organs were examined by ultrasonography. Urinary iodine was determined by catalytic spectrophotometry with arsenic and cerium. The nutritional status of iodine was classified into iodine deficiency(<100 μg/L), iodine adequacy(100-199 μg/L), iodine adequacy(200-299 μg/L) and iodine excess(≥300 μg/L). Non-parametric test was used to compare urinary iodine level between HT group and control group, one-way ANOVA and t test were used to compare urinary iodine level between HT group and control group, and Spearman correlation analysis was used to compare the correlation between urinary iodine level and T3, T4, TSH, ATG and TPOAb under different iodine nutrition status. Results Compared with control group, ATG and TPOAb levels in HT group increased(P<0.001), and urinary iodine levels increased(P<0.05), with statistical significance. Compared with the control group in different thyroid function states, only the HT group with hypothyroidism increased the urinary iodine level(P<0.01), and the difference was statistically significant. Spearman correlation analysis showed that urine iodine level was positively correlated with ATG and TPOAb levels in iodine excess condition(P<0.05), and urine iodine level was positively correlated with TSH level in iodine sufficient condition and iodine excess condition in HT patients(P<0.05). Conclusion The urinary iodine level of HT patients was higher than that of normal people. When the urinary iodine level of residents is ≥300 μg/L, iodine intake is prone to HT. When the urinary iodine level of HT patients is ≥200 μg/L, iodine consumption is prone to hypothyroidism, and iodine intake should be limited.