Heading impact influences on brain during a soccer game such as concussion have been repeatedly reported in the statistical or neuropsychological basis. Even though, overall evaluations or conclusions have yet to be determined because few report have discussed the heading impact in the point of mechanics inside the brain. In this paper, a numerical impact analysis between a computed-tomography oriented voxel model on human head and a soccer ball expressed by shell elements has been performed. We prepared the head model of child and adult, the soccer ball for children and adults. We investigate the analysis results in the point of maximum principal strain and head injury criterion (HIC). The child head is modeled to be 0.9 times the size of the adult models from ratio of head circumference. The child ball model is 0.93 times the size of the adult ball models by the FIFA provisions size. We perform analysis on adult soccer ball and adult (Case a), child's soccer ball and the child (Case b). Case a maximum principal strain is 5.9% in the spinal cord, HIC is 102. Case b maximum principal strain is 4.6% in the spinal cord, HIC is 75.5.