Purpose : The purpose of this study was to investigate characteristics of the forced pulmonary function test effect by changes in lung function related to postures and by Transverse Abdominis(TrA). Contraction in standing position during forced inspiration and expiration with young female adults. Methods : 10 young female adults were recruited this study. pulmonary Function test was measured with a Master-screen Body (VIASYS Inc., CA, 미국). To check the changes in lung function with different postures, we tested pulmonary function in the standing and supine position each. In the standing position, while the transversus abdominis was activating, we compared the forced inspiration with the forced expiration. Statistical analysis was used Independent t-test to know difference between forced inspiration and expiration of activated TrA. Results : According to the study, the change of pulmonary function were statistically significant difference in the standing compared to the supine position. The contraction of the transversus abdominis causes decrease in the change of forced inspiration and increase in the change of forced expiration. Conclusion : These results indicate that spontaneous contraction of the TrA in standing position helps pulmonary function. And the selective contraction of the transversus abdominis at the end of forced inspiration makes increases in the forced expiration.