An objective evaluation of the degree of respiratory impairment in children depends on the establishment of standards of normal function. In addition to sex and growth, various factors such as race and geography have been shown to be important determinants of lung function. The purposes of this paper are to report the result of lung function tests performed on a group of healthy children, to define the range of normal values, to provide a prediction formula of each parameter, and to compare the data with those of other investigators. Pulmonary function tests were performed on 198 healthy normal children in Kwangju between the ages of 5 and 15 years. The following variables were measured: vital capacity, forced vital capacity, one-second forced expiratory volume, peak expiratory flow, and maximal expiratory flow at 25%, 50% of expiratory vital capacity. Simple and complex prediction formulas for variables of PFT are presented according to sex, age, height, weight, and body surface area. 1) With increasing age, height and weight development increased in both sexes and their mean values in each age groups were more higer than those of Korean standard for children. 2) The correlation coefficients were 0.8 or more more in VC, FVC, FEV1 & more higher than that of PEFR, V25, V50. 3) Of the parameters examined, height had the heighest correlation coefficient in all pulmonary function test items. 4) The correlation coefficients by age, weight, body surface area were similar, but according to sex each parameters of PFT varied slightly. 5) Among complex prediction formulas, the correlation coefficients by 3 variables (age, height, and weight) and 2 variables (height and weight) were more higher than others. But disregarding age and weight, the correlation coefficients of height resembled that of simple regression equation. 6) Predicted values of pulmonary function test and correlation coefficients to the parameters were generally higher in boys than those of girls.