Abstract: Vehicle lateral and oblique impacts account for a large proportion of traffic accidents resulting in serious occupant injuries. There is a lack of adequate investigations into the thoracic injury biomechanics in lateral and oblique impacts, compared to thoracic injuries in frontal impacts. Therefore, this article aims to study the biomechanical response and injury related parameters of the thorax under these two impact scenarios. First, an FE model of entire human body in sitting posture is established via combining previously developed FE models of the thorax, the head-neck and the lower extremities. Afterwards, the sitting human body FE model is used to simulate the 7 cadaver experiments by Shaw et al. in lateral and oblique impact to thorax. The calculated injury related response curves of the impact force, thorax deformation, and force-deformation are correspondingly within the biomechanical response curve corridors from experiments, which verified the validity of the sitting human body model. The peak value of impact force is close to the upper boundary of the test corridor, and the deformation approaches the lower boundary of the experimental results. Meanwhile, the peak of impact force from the lateral impact simulations is slightly larger than the resulting peak from oblique impact, and the peak of the timing is earlier. The peak of chest deformation in lateral impacts is smaller than that from the oblique impact, and the peak also appears earlier. This presents a trend consistent with the experimental results. Analysis shows that under the same intensity of impact load the thorax tolerance in lateral impact is higher than that in oblique impact. The thorax finite element model can accurately reproduce biomechanical response process in the lateral and oblique experiments. The model demonstrates good biofidelity to study the occupant thorax injury biomechanics.