In vehicle-pedestrian impact, the majority of pedestrian fatalities are caused by head injuries. Accident analysis showed that bonnet of car often had consequences with severe head injuries in accidents involving young pedestrians. Important factor involving risk of head injury is design of bonnet structure. The injury risks to the head by such an impact were examined by child headform impact test. HIC value and deformation were the main criteria for assessing of bonnet pedestrian friendliness. Different bonnet modifications were examined using mathematical simulation of such a test and their benefit for child head injury risk reduction was assessed.