This study is to analysis the effect of circuling exercise program after school on body fat%, vascular variables,
artery stenosis and leptin during 12 weeks in obese children. The subjects was composed of experimental
group(n=9) and the control group(n=9). The subjects were measured to body fat%, leptin hormone and
vascular variables using ultrasound doppler. As a result, In the case of fat%, resistance index, arterial stenosis
index represents having significantly(p<.001) a high reduction ratio but the control group did not change
significantly. Leptin in the control group not change significantly recorded a lower decline but experimental
group significantly(p<.001) higher according to the reduction of body fat. Through the reduction of the leptin
hormone in change of vascular factors, body fat, obesity boys were able to observe the improvement leptin
resistance and the blood system to adapt to the exercise of long-term. Therefore the circuling exercise
program presented in this study is considered a positive impact changes in leptin, the functional development
of vascular and resolved obesity. Forward, It is presented effective after-school sports program for
improvement of obesity-related hormone, decreased body fat and cardiovascular function in obesity boys.