Body index is known as it affects pulmonary function tests (PFT), so it has been used with predictive formula and nomogram in terms of sex, age, height, etc. Body indices as body weight, body mass index (BMI), and body surface area (BSA) might also affect PFT, so that we have analyzed the correlations between body indices and forced expiratory volume in one second (FEV1), and have done multiple regression analysis to see how body indices affect FEV1. We confirmed that FEV1 had positive correlations with height (r=0.49, p<0.01), body weight (r=0.37, p<0.01), and BSA (r=0.47, p<0.01), inverse correlation with age (r=-0.45, p<0.01), but no correlation with BMI. We found that the 41.9% of FEV1 was diverged from height, age and BSA. Therefore, BSA definitely needs to be considered with predictive formula and nomogram in PFT.