It is helpful in lithography process and developing resist to know the relationship between the critical dimension variation and simulation parameters such as aerial image parameters, the Dill exposure parameters, PEB (Post Exposure Bake) parameters, and development parameters. In this paper the profiles of a 193 nm CAR (Chemically Amplified Resist) were simulated with those various parameter, and those results were analyzed by the response surface methodology (RSM) approach to know the influence of independent factors on a dependent response and to optimize each process. Both the parameter effects of each process and the simulation process effects of the whole process were described about critical dimension and side wall angle so that the sensitivity of lithography process could be assumed. The development parameters were modified with those of flood exposure experiment according to the pattern density and pattern size for more accurate lithography simulation. Also those effects on critical dimension and side wall angle were analyzed. For the validity of our results the quantitative comparison between our results and those of a commercial tool was shown.