Increasing number of vehicles and the demand for high speed of road traortation, as well as occurring undeniable accidents and causing human and property damage in accidents and also due to field and laboratory tests cost, the need to study the vehicle structure and safety to determine the final quality and vehicle assessment based on the simulation has been considered. In this case, the use of computer software such as RADIOSS, can be useful to simulate crash tests as one of the most powerful tools for simulation crashworthiness issues in the field of vehicles. In this study, early simulations based on the standard testing are conducted in a frontal impact, side impact and roof strength. Then, based on the crashworthiness improvement approach, three methods are adopted for this purpose. Initially, using the CES EDUPACK software came to investigate and determine the optimal material properties that analyzing specifications, Advanced High-Strength Steels are selected. This type of steels, with advantages such as low density and cost, extraordinary strength and toughness as a material suitable for use in vehicle body structures are considered. The use of these materials in vehicle structures and resimulating, the results and crashworthiness are discussed. It is observed that the vehicle characteristics such as the crush, intrusion, velocity, acceleration and energy absorption of components has been improved. The next method to crashworthiness improvement is change in the structure, such as change in the bumper and inside the car door that can be noted to add absorber foam core in front of bumper, placing foam or honeycomb core sandwich panel inside the doors. Finally, vehicle structural reinforcement is considered to review crashworthiness improvement of the main components in the energy absorbing zones in front, side and roof of the vehicle. Keywords: Crashworthiness, Crash Test, Finite Element Method, RADIOSS, Crush, Advanced High-Strength Steels, Collision Energy Absorption.