We have examined 15,145 persons(7,468 men, 7,677 women) to determine the role of Obesity Index(body mass index, WHR, body fat percent) on the risk of various chronic disease. All the subjects were pooled from Health Examination Center who took the annual health examination from June, 1994 through Jan, 1997. BMI(Body mass index, kg/m2), WHR(Waist hip ratio) were measured and correlated with the frequency of chronic disease. In order to evaluated the BMI, WHR, Body Fat as an independent factors on morbidity, analysis of covariance was applied adjusted for age. The risk of various chronic diseases were also analyzed with obesity, defined by BMI above 26 kg/m2(men), 25 kg/m2(women), by logistic regression adjusted age and sex. Risk of hypertension was 2.6 with 95% confidence interval of 1.9~2.8 in obese group. Risk of diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, gall stone, fatty liver were 3.2(2.3~4.4), 1.2(0.9~1.4), 2.1(1.7~2.8), 1.4(1.1~2.6) and 1.3(0.8~2.3) respectively. The risk of various chronic diseases were also analyzed with obesity, WHR above 0.9(men), 0.81(women), by logistic regression adjusted age and sex. Risk of hypertension was 1.7 with 95% confidence interval of 1.4~2.1 in obese group. Risk of diabetes mellitus, hypercholesterolemia, hypertriglyceridemia, gall stone, fatty liver were 3.1(2.3~4.0), 1.2(0.9~1.4), 1.4(1.1~2.6), 2.4(1.8~4.8) and 2.1(1.2~4.1) respectively. The BMI, WHR were independent risk factors for various chronic diseases.