Background/Objectives: To analyze changes in the incidence of thyroid cancer for Korean population using big data from the National Health Insurance Service. Materials & Methods: Sample cohort database between January 2004 and December 2013 with 1,000,000 cases for each year was enrolled in this study. Thyroid cancer incidence was analyzed by sex, age and by region. Public health insurance payment was used to reflect socioeconomic status. Results: The incidence of thyroid cancer in Korea increased for 10 years annually. There are 3 times increasing in the incidence rate of thyroid cancer from 2004, 0.03% to 2013, 0.09%. The sex ratio in the incidence rate of thyroid cancer was male : female = 1:7.2 in 2004 and male : female = 1:3.6 in 2013 that suggest decreased gap between the sex ratio. Between 2004 and 2010, the incidence rates of those in their 40s were found to be the highest, whereas the incidence rates for those in their 50s were found to be highest from 2011 and thereafter. Every year the high socioeconomic status group showed a higher incidence of thyroid cancer than low socioeconomic status group. Some specific region showed continuous high incidence of thyroid cancer, not all city and state. Conclusion: The incidence rate of thyroid cancer for 10 years had special feature by sex, age, socioeconomic status and especially by region. This results will be a barometer for further epidemiologic study about the incidence of thyroid cancer for Korean population