Abstract: Objective In the last few decades, the incidence of thyroid cancer has been found rapidly increased worldwide as well as in China. It is suspected that this increasing might be related to the iodine over-intake since the introduction of USI. However, the results were of inconsistence, and we aim to look into this relationship in Shenzhen. Methods A total of 123 patients with diagnosis of thyroid cancer (TC) and 150 patients with nodular goiter were consecutively recruited while 102 normal subjects were randomly selected as control group in comparing the urine Iodine levels. The thyroid hormones, thyroid autoantibodies in serum were also measured. Life-style and social economic factors were collected. Anxiety and stress were scored by questionnaires and compared among the three groups. Results There was no significant difference between the TC group, nodular goiter group and control group in terms of urine iodine levels (120.2±118.9μg/L, 128.5±136μg/L vs. 124.5±124μg/L; F=0.32, P=0.572). Multiple regression analysis indicated that the thyroid cancer incidence was significantly associated with patient’s marital status, education levels, higher BMI (P<0.05) and anxiety scores. Conclusion Incidence of thyroid cancer is not significant associated with patient’s urine Iodine level but associated with the life-style factors such as obesity, divorce, education and anxiety.