Abstract: Objective This study is to predict and assess the biomechanical responses and injury mechanisms of the fifth percentile female thoracic-abdominal in traffic accidents. Methods The accurate geometric model of thorax and abdomen was constructed based on the CT images of Chinese fifth percentile female volunteers. A thoracic-abdominal finite element model （Pam-crash version） was developed with detailed anatomical structure of Chinese fifth percentile female by using the corresponding software. The model was validated by reconstructing three groups of cadaver experiments. Results The force-deformation curves and injury biomechanics responses of the organs from the simulations were consistent with the cadaver experiments results. Conclusions The model can be used to study the thorax and abdomen injury mechanisms of small-sized female. This model will help to develop the 5th female occupant restraint systems and analyze the forensic cases. This is an important component for developing the fifth percentile Chinese female whole body finite element model.