Purpose : This survey was to investigate on the effect of each region changed in trunk through sagittal plane after Trunk Flexion-Extension Exercise. Methods : 18 students of Gimcheon College participated in this study for the period of July 9-30, 2007. Analyzed factor were 1) degree of pain 2) presence of Gillet test and 3) difference of right-left for 7 landmark region in trunk applying I.B.S.-2000 after Trunk Flexion - Extension Exercise. We used the SPSS $PC^+$ program for classifying into analysis of frequency, $x^2$-test, t-test and Simple Linear Regression analysis test. Results: Followings are concluded For degree of pain, 13(72.2%) of students answered "No pain" after Trunk Flexion-Extension Exercise and in the result 4 more students decreased the pain. In the Gillet test, 14(77.8%) of students answered "positive" after Trunk Flexion-Extension Exercise and in the result 4 more students increased mobility of Sacroiliac joint. In the differences of right-left for 7 landmark region in trunk by B.M.I. scale, Slim type was decreased both Acromion(0.45mm), both Iliac crest(0.44mm), and both ASIS(0.31mm) to anterior plane, Normal type was decreased both inferior angle of Scapular(0.02mm), both L4-5(0.07mm), and both PSIS(0.09mm) to posterior plane Fatness type was decrease both Acromion(0.05mm), both ASIS(0.05mm) to anterior plane. In the differences of right-left for 7 landmark region in trunk for degree of pain No pain group was decreased both Acromion(0.17mm), both Nipple(0.25mm) to anterior plane and both PSIS(0.13mm) to posterior plane Pain group was decreased both Acromion(0.04mm), both Iliac creast(0.03mm) to anterior plane and both inferior angle of Scapular(0.18mm) both PSIS(0.13mm) to posterior plane. In the difference of right-left for 7 landmark region in trunk for each of the exercises, Both iliac crest(0.1mm), both ASIS(0.12mm) to anterior plane were decreased after Flexion Trunk Exercise. Both acromion(0.27mm) to anterior plane, both inferior angle of scapular(0.14mm) and both PSIS(0.12mm) to posterior plane were decreased after Extension Trunk Exercise. Each of the exercises, The both inferior angle of Scapular showed high scores($0.65{pm}0.23$) at Trunk Extension Exercise group and there was statistical significance between Trunk Flexion Exercise group and Extension exercise group(t :-2.502, p < 0.05). 7. At Pre-exercise group, Both inferior angle of Scapular showed low scores($0.23{pm}8.27$) at Trunk Extension Exercise group and there was statistical significance between Pre- Exercise group and Trunk Extension Exercise group(t :-2.5430, p<0.05). Conclusion : The simple linear regression analysis was presented at Acromion(-0.243), L4-5(-0.753), PSIS(0.576) and there was statistical significance in BMI scale(p<0.01).