Even though rear-end crashes are third among various collision types, occupant injuries from these incidents contribute for around one-third of all collisions. The National Highway Traffic Safety Administration (NHTSA) provides standards including the Federal Motor Vehicle Safety Standards (FMVSS) related to the vehicle structural crash responses as well as car occupant injuries. This thesis is mainly focused on the structural damage of a small compact car in Full-Width, Offset and Oblique-Offset Rear-End collisions, and evaluation of the potential neck injuries to the LEFT and RIGHT rear occupants of the car. To accomplish this, LS-DYNA simulations are performed using finite element (FE) models with rigid and deformable barriers according to the FMVSS 301 old and new regulations. Based on accelerations extracted at LEFT and RIGHT occupants, a car seat cabin configuration model in MADYMO with seat belt and a Hybrid-III 50th percentile dummy is developed. The occupant responses and kinematics of rear occupants (both LEFT and RIGHT) are examined in different rear end collisions including the Full-Width, Offset and Oblique-Offset rear end collisions. In addition to this Oblique-Offset Rear-Impact is also performed for better analysis of occupant responses at the near-side impact and the interaction of two rear occupants, to examine the proposed Oblique-Offset Rear-End Collision and to make recommendation on its use as regulatory standard. The results obtained from this study illustrates the difference of structural responses and evaluation of potential injuries of occupants in Full-Width, Offset, and Oblique-Offset Rear-End Collisions. The study also recommends that the Oblique-Offset Rear-Impact with two rear occupants to be part of the new Rear-End collision standard and that the secondary impact, including the Head Injury Criteria (HIC) to be evaluated for the occupants.