The purpose of this study is development of computer based testing to measure obesity risk factor for Korean adults. To increase validity and reliability, This study accomplished pilot test(N=445) and real test(N=1115). Based on the literature review and consultation of content and measurement experts, the 4O-item Obesity Risk Measurement Scale was generated. The pilot test data was analyzed through exploratory factor analysis through SPSS program. It was 21-item consists of six factors(physical activity 6-item, meal habit 3-item, sneck 3-item, gluttony 3-item, psychology 3-item, heredity 3-item) constructed. The real test data was analyzed through confirmatory factor analysis through AMOS program. It was 19-item consists of six factors(physical activity 4-item, meal habit 3-item, sneck 3-item, gluttony 3-item, psychology 3-item, heredity 3-item), that two items were eliminated in the physical activity factor. The computer based testing in this study was on internet site (http://www.ezday.co.kr/miz/health/diet_poll.html?q_left_menu=miz_diet) using text language (HTML: hyper text marup language) and server script language(PHP: personal hypertext preprocessor). Rasch model measurement computer program, Bayesian 1.0 was used to analyze the data. The computer based testing shows obesity risk percentage at the each factors statistically.