The purpose of this study was to examine body composition changes, selected factors of physical fitness and the inter-relationships among them in beginner adolescent in response to three months' volleyball exercise training. 28 nonprofessional volleyball players of "Shomal Sports Complex" participated in this study. The exercise training program was performed in three months (three inconsecutive days a week and 1.5-2 hours per session). The factors for measurement included height, weight, body mass index (BMI), circumference and skin fold of selected parts of body, body composition factors, anaerobic tests, agility tests, dynamic test or muscular endurance. The results found from data analysis (using Paired Sample test, in level of a=0.05) suggest that an insignificant increase was observed in body weight and 8MI, a significant decrease found in %BF, FM, skin folds of triceps, femur, subscapular is, abdomen and chest, a significant increase observed in FFM, circumferences of arm, elbow, femur, calf abdomen and chest, an insignificant decrease was found in calf skin fold. Also a significant increase was observed in vertical jump, length jump, to & fro and jump upon line, a significant decrease found in 4x9 meter of agility and an insignificant increase was observed in sit up.No significant correlation was found among body composition factors (length of inferior limp, high, weight, BMI, %BF, FM and FFM) with selected tests of physical fitness, either before the start of exercise training or after it. However, a major reason of progression in physical fitness record could be improvement in body composition result in regular exercise training.