With rapidly shrinking feature sizes, full chip robust Optical Proximity Correction (OPC) will take longer due to the increasing pattern density. Furthermore, to achieve a perfect OPC control recipe becomes more difficult. The critical dimension of the design features is smaller than the exposure wavelength, and there is only limited room for the OPC correction. Usually very complicated scripts need to be developed to handle the shrinking designs. So when you are defining a parameter value in your OPC control recipe, one problem is how to find the optimum setting. Usually there are many parameters in the script, some of which may have impact on others' performance. We demonstrate an approach to optimizing the critical parameters settings with cost functions to reduce the difficulty of OPC recipe development.