The purpose of this study was to examine the effects of 8 weeks high or low intensity endurance or strength training on body composition in normal persons. And the second purpose was to investigate the changes of body composition after 4 weeks detraining. Twenty-three normal men were matched and randomly placed into three groups; a group that performed running exercise on treadmill three times a week, 20 minutes per session at 85%VO2max (H; N=9); a group that performed walking exercise three times a week, 30 minutes per session at 50%VO2max (L; N=9); and a group that performed strength training three times a week, 3 sets of 15 RM per session (S; N5). 8 weeks different exercise training insignificantly influenced on the body composition included body weight, percent body fat, fat mass, fat-free mass, muscle mass, and bone mass. However, the cardiorespiratory function and muscular strengthen were significantly improved. The variables of body composition were also unchanged after one month detraining. After 8 week’ different exercise training, the body weight of all groups was tiny increment but not significant (P＞0.05), the highest increment was in H group (1.08 ± 1.77 kg), and the lowest was in S (0.34 ± 0.73 kg). After training, the percent of body mass increment attributed to fat for the H, L, and S groups was 81%, 73%, and 153%, respectively. The short-term weight-loss program merely applying exercise intervention should not significantly change the body composition.