Collision behavior of TPU(thermoplastic polyurethane elastomer) airbags were analyzed using two and three dimensional numerical methods to understand the effects of process parameters such as internal pressure, material properties, speed of air leakage on collision performance. The analysis results were also compared with experimental results. The internal pressure was confirmed to affect the collision performance significantly, as it increases to a certain degree showing favorable contribution. Also, air leakage was considered in order to further enhance the collision behavior.