In this study, the relation between various impact loadings and intracranial pressure of a human head model is studied. Firstly the pressure response of sealed acrylic water container under impact loading is obtained experimentally and by FEM, and both results are compared. After verifying the numerical method, the various impact loadings are given on the 3D finite element human head model. Under the condition of constant energy impact, the velocity gives more influence than the mass on the intracranial response. Stroke of high speed/small mass causes vibration of skull with rather high frequency and stroke of low speed/large mass causes positive pressure on impact side and negative pressure on the opposite side of the impact and does not cause vibration. If brain cells are damaged by negative pressure, this result would agree with the following theory by legal medicine: Stroke with short time duration tends to cause both coup and contrecoup contusion simultaneously, on the other hand stroke by fall down tends to cause contrecoup contusion.