In Japan, accidental injury tops the list of the cause of child (1 to 19-year-old) death. This has continued since 1960. We pay attention about "Shaking baby syndrome" and influence the brain in the head that cannot be judged from the face. This is a syndrome to occur by abuse mainly. Currently, an intentional injury act such as this abuse is problem. In abuses, it is thought that the head injury of infant is the highest risk of death. In this head injury, there is not a clear standard for judgment that the head injury of infants is caused by abuse or an unexpected accident. So, to establish the standard, development of the technique that can estimate an injury process by objective information such as injury information and the spot information is demanded. I think it needs to understand the injury by abuse to discriminate from unexpected accident. I understand the injury by experiment. I use the child dummy doll for six months in experiment. I conduct two kinds of shake experiments by person and the vibration exciter. I change a parameter of the vibration such as acceleration, frequency, amplitude, phase difference using the vibration exciter. Therefore, the influence that the vibration exerts on the infant head was verified. As the result of experiments, I supposed high-risk frequency in shaking events.