The potential of head injury in frontal barrier impact tests was investigated by a mathematical model which consisted of a finite element human head model, a four segments rigid dynamic neck model, a rigid body occupant model, and a lumped-mass vehicle structure model. The finite element human head model represents anatomically an average adult head. The rigid body occupant model simulates an average adult male. The structure model simulates the interior space and the dynamic characteristics of a vehicle. The neck model integrates the finite element human head to the occupant body to give a more realistic kinematic head motion in a barrier crash test.Model responses were compared with experimental cadaveric data and vehicle crash data for the purpose of model validation to ensure model accuracy. Model results show a good agreement with those of the tests. The model was then used to assess head injury severity in the cases when the occupant was restrained by an airbag only (31 mph barrier test) and by an airbag and a 3-point belt (35 mph barrier test). Head acceleration, stress and strain in the brain were investigated as injury parameter indicators. The model advances the study of brain motions and accompanying stresses during large linear and angular displacements encountered in vehicle frontal collisions.