In a study of 240 persons, 121 males and 119 females, aged on 6 to 18, the author demonstrated the relation between phonation time and phonic breath volume in Koreans. The test is performed in the following manner. After a few trials, the person takes a deep breath and phonates vowels as A,E,I,O and U on a desired pitches e' (330 cps) and a' (440 cps) each for a long as possible but tone could be phonated musically useful sostenuto. The vital capacity volume was measured with Hutchinson's spirometer, and measured the phonation time in seconds with stop-watch during which a particular tone can by phonated on one exhalation, and also phonic breath volume were calculated. The author has obtained the following results ; 1) The vital capacity volume shows 2,692 cc in male, 2,158 cc in female, 2,425 cc in average, and their sex difference is 534 cc. 2) The phonation time in average is 16.05 seconds, and it is longer at e' (330 cps) than at a' (440 cps) level and also longer on U,O,I,E and A utterances in the order. 3) The phonic breath volume in average is 151.11 cc.