In vehicle collisions, vehicle accelerates and rotates during impacts, though three-dimensional rotation is generally not reflected in simulation analyses.The objective of this study is to understand the effects of car rotation on occupant kinematic behavior in vehicle impact with rotation.The method to provide the boundary condition for the occupants under car acceleration and rotation was formulated.The kinematics of occupant FE model was calculated under vehicle rotation conditions.Two crash cases with vehicle rotation were examined: small overlap frontal crash (yawing) and full-width crash tests (pitching).In the small overlap frontal test simulation, the head lateral displacement of occupant was almost the same in the conditions with and without vehicle yawing angle.The results of full frontal car simulation with pitching showed that the occupant acceleration was mitigated since the seatbelt anchor moved forward together with the occupant.Rotation angles of car influence the occupant kinematics, and it is necessary to include the car rotation to simulate the occupant kinematics in vehicle collisions.