Now, we have experienced that the loss ratio of cancer insurance with prevalence of cancer increased. The insurance companies interest how the loss ratio of cancer insurance decrease. To decrease the loss of ratio of cancer, underwriting is very important. The underwriting of cancer are very important factors which are family history, habitual behavior and past history. We have spend the most of time under the occupational situation. Occupation may be very important factor causing cancer. But we neglect the occupation history. This article show how the underwriting of the occupational cancers in the field of occupation are managed Generally, Occupational cancers show special characteristic features. We know the characteristics of occupational cancer under the variety of occupation. For the underwriting of occupational cancer in Korea, we also understand the epidemiology of Korean occupational cancer with the varieties of occupation This article shows the characteristics of occupational cancer and epidemiology of Korean occupational cancers.