The purpose of this study investigated the influence of male middle school students changes of GH, IGF-Ⅰ, Height, Body composition after 10weeks stretch-shortening training program. Male middle school students(N=14) were divided into experimental group(N=7) and control group(N=7). Stretch-shortening training were consisted of pogo(80%HRmax), rocket jump(85%), box jump single response(90%), stride jump crossover(90%), quick leap(80%), depth jump(85%), double-leg incline and stair bound(90%). Each subject trained on plyometrics for 10weeks, 3days per week for 1hour a day. Subjects underwent an Insulin Tolerance Test by injection of 0.1U/kg regular insulin and blood samples for GH assay were taken at 0, 30, 60 and 120 minute. The results are as follows. 1. In body composition height(p<0.01) and muscle mass(p<0.05) increased significantly. But %fat(p<0.05) decreased significantly. 2. Subjects underwent an ITT by injection of 0.1U/kg of regular insulin and blood samples for growth hormone assay were taken at 0, 30, 60 and 120 minute. Maximum level of GH were experimental group 30min and control group 60min. 3. Experimental group(p<0.001) and control group(p<0.05) increased significantly in IGF-I level. As a result, high intensity stretch-shortening training catalyzed growth and IGF-I of male middle school students. Thus, stretch-shortening training was effected positive in growth development.