In this paper, a bulging condition which affect the quality of continuous casting steel was analyzed by using the numerical analytic method. First, solidification analyses were performed for each cooling zone by one-dimensional finite difference method. The bulging deformation of cast slab has been calculated with a two-dimensional elasto-plastic and creep finite element model. The adequacy of the model has been checked against the experimental results. From this study the effects of the process variables such as casting speed, cooling condition and roll pitch were examined. The results from these analyses would be able to apply to the design of continuous casting process.