Abstract: By considering the practical assembly process of the body bolster, Welding structure analysis system (Weld-Sta) is employed to predict the welding deformation of the structure. Firstly, finite element models and welding lines of each step are constructed. Then, the welding deformation of each step is calculated in corresponding model. Thirdly, the whole welding deformation is summed up by the one from each steps. Finally, the welding deformation of the structure is calculated in one step. By comparing the welding deformation predicted by simulated results including two methods-considering welding sequence and not considering welding sequence with that of measured results, the reliability of this method is confirmed. This study can provide a guideline for the designation and determination of welding procedures on body bolster.