The purpose of the present study was to investigate the effects of a period of military service physicalfitness and body composition camponents in police soldiers.For this purpose from 200 soldiers; 124 were selected nonrandomly. The mean age of the subjectswas 22.9±0.34 yrs; also weight and height of subjects were accordingly 74.3±13.3 kg and 170.3±9.27cm.The method of the study was explained to the subjects; and they filled up the informed consent andmedical-sport forms. Then subject participated in military service training for two month. Physicalfitness and body composition components were measured at pre-post tests accordingly:1. Local endurance of abdominal muscles by using sit-up tests (2 min): 2. Power of the leg musclesby using standing long jump test; 3. Speed; by using 60 meter run test; 4. Shoulder girdle muscleendurance by using push-up test (2 min): 5. Agility; by using 4x9 m. back & forth run test; 6. Cardiorespiratoryendurance by using 3200 m. run test. Skinfold fat of the subjects were measured; andaccording to that; percent body fat and fat free mass were computed. At the end; the t- student testwas used to compare the pre and post-tests.The results of this study revealed that there is a significant increase in cardio-respiratory endurance;local endurance of abdominal muscles; shoulder girdle muscle endurance; power; speed and agility(P≤0.05). A significant decrease was indicated in body weight; percent body fat and fat mass of thesubjects (P≤0.05). On the other hand; a significant decrease; was also observed in fat free mass.Therefore it can be concluded that a period of military service training caused significant changes inphysical fitness and body composition components. However; there are two points of considerationmentioned below;1. Significant decrease in body fat in order to improve the physical fitness of the subjects isexplainable; however significant decrease of weight and fat free mass concerns other variables relatedto physical fitness and body composition; such as sleep; and rest; nutrition and other psychologicalfactors.2. The significant increase of all physical fitness components of the subjects is not an indication of ahigh quality-training program. Because; the results of the subjects pre and post-tests and comparingthem to reliable norms indicated that they were very weak; and even in post-test.