In this study, we aimed to compare elementary school boys’ (10-13 age group) body composition that exercise and do not exercise by the method of bioelectrical impedance analysis (BIA). Totally 38 male student of primary school level took part in the study. Experimental group consists of 22 male students whose age average 11.27 ± 0.63 year, height average 142.7 ± 8.06 cm, weight average 37.95 ± 7.68 and who regularly practice football 2 hours in a day and 3 days in a week. Control group comprise of 16 male student whose age average 11.87 ± 1.40 year, height average 147.0 ± 10.99 cm, weight average 37.55 ± 11.04 kg and who isn’t regularly exercise. Experimental and control group’s body composition evaluated by the method of bioelectrical impedance analysis. We have found significant differences on body mass index, body fat mass of the experimental and control group’s (p<0.001), resistance measurement value and the phase angle (p<0.005). As a result, regular exercise has positive effect on the body composition at children.