Aerobic power (VO_2max) is an important indicator of the health and physical fitness. Executive problems in direct VO_2max measurement has led to developing sub-maximal aerobic power prediction equations. The purpose of present study was to develop native aerobic power prediction equation based on 6-Minute Walk Test (6MWT) and body composition indices in children. In 192 healthy children (8 to 12 years) VO_2max was objectively measured by Bruce treadmill protocol with gas analysis. The 6MWT was performed according to ATS guidelines. Also, anthropometric measurements were measured according to standard methods. Multiple regression analysis was used to design aerobic power (ml/kg/min) prediction equation. Accuracy of native VO_2max prediction equation was assessed by Pearson correlation and Bland-Altman approach between measured and predicted VO2max. Significant correlation was observed between direct VO2max and independent variables (r=0.25-0.734). Aerobic power of the boys could be predicted by weight and 6MWT according to the following equation: VO_2max(ml/kg/min)= 5.359 + (0.067 × 6MWD m) – (0.286 × Weight kg) (r²=0.743, SEE=2.74 ml/kg/min, p≤0.001). Strong correlation was observed between measured and predicted VO2max (r=0.861, P≤0.001). In addition, Bland and Altman plots demonstrated a high degree of consistency between measured and predicted VO2max. Exercise and fitness coaches by utilization of native aerobic prediction equation based on the 6MWT and weight could be able to assess the aerobic power of the boys and to evaluation of the effects of exercise training on cardio-respiratory fitness.