The fact that helmets can prevent head injury is well-established. This paper describes the use of a dynamic, inelastic and large deformation finite element code LS-DYNA3D to simulate the impact response of motorcycle helmets. In order to verify the accuracy of the model, the simulation results of helmet drop on steel anvils were compared with experiments. The numerical predicted results matched experimental data very well. We then study the effects of ventilation holes. EPS shell with ventilation holes absorbed shock better than intact one when impacting the flat anvil, but not when impacting the hemi-sherical anvil. Next, a full FEM model which contain Hybrid III head, neck, and chest has been developed and couple with helmet FEM model for analyzing the kinematics of the neck motion and the associated dynamic transient response of the head subjected to various impact angles. The critical characteristics such as head C.G. acceleration, section forces and moments at the head-neck section and neck-chest section are investigated for each cases. Thus we have established a reliable 3D finite element model which can help us to better design the helmet.