Objectives: The purpose of this study is to examine the risk factors and the genetic polymorphism of TNF-alpha associated with rheumatoid arthritis by Sasang constitution Methods : This study was planned to detect the susceptibility of the patients diagnosed by rheumatoid arthritis to Sasang Constitution and to examine the risk factor such as life style and environmental stress (smoking, environmental tobacco smoke, alcohol intake and so on). The genetic polymorphism of TNF-alpha (G308A) were analyzed by PCR-RFLP in rheumatoid arthritis patients and controls. Rheumatoid arthritis patients and matched controls are assessed with QSCCII question for Sasang Typology. Then the genetic polymorphism of patients by Sasang constitution are compared to those of control, which are statistically analyzed and adjusted by age, sex, smoking status, alcohol intake, BMI, and econocmic status. Results: Differential effect of passive smoking on the association between Sasang constitution and rheumatoid arthritis risk was found. This study showed that the genetic polymorphism (TNF-${alpha}$(G308A)) of rheumatoid arthritis patients and controls associated with the susceptibility to rheumatoid arthritis by sasang constitution was analyzed. Differential effects of TNF-${alpha}$(G308) genetic polymorphism on the association between rheumatoid arthritis risk and Sasang constitution were found. Conclusion : It is suggested that the genetic polymorphism correlated with susceptibility to rheumatoid arthritis by specific sasang constitution used as its susceptibility marker and further as basic data to prevent the risk factors for rheumatoid arthritis. But larger studies will be needed to confirm these preliminary findings.