Since pulmonary function testing was first described by Hutchinson in 1846, this technic has been developed by many physiologists and applied to clinical fields for eviluation of cardiopulmonary status in order to improve diagnosis and treatment of cardiopulmonary diseases. The normal values of the lung volumes and capacities, maximal midexpiratory flow, maximal breathing capacity and forced expiratory volume and time in 120 (male-60, female-60) normal Korean adults by using a Gaensler-Collins bronchospirometer are presented. The results were as follows: 1. The vital capacity of the normal Korean adult was 4191±451ml. for males and 2685±375 ml. for females. 2. The ratio of inspiratory capacity to vital capacity for males was 66± 9% and for females 70± 7%, but that of expiratory reserve volume to vital capacity for males was 34±9% and for females was 30±7%. The ratio of inspiratory capacity to vital capacity of normal Korean adults is slightly lower than that of whites, while that of expiratory reserve volume to vital capacity of normal Korean adults is slightly higher than that of whites. 3. The maximal breathing capacity of males was 95± 171/min. and that of females 61±141/min. 4. The maxima mid-expiratory flow for males was 266± 711/min. and for females 176± 421 /min. The maximal mid-expiratory time of males was 0. 497± 0.145 second and that of females 0. 479± 0. 128 second.