Die and mold are constructed with various free surfaces. In the machining of die and mold, it takes a long time to finish the curved surface. In this study high accurate polishing technique by GC (grinding center) with elastic ball type wheel is developed. In polishing process it is very important to remove cusp height without decreasing machined form accuracy. It is available to use GC in free surface grinding and finishing of die and mold with elastic ball type wheel. In polishing process only cusp height is removed in order to keep form accuracy that is produced in cutting process with ball end mill. In order to know the polishing characteristics of elastic ball type wheel, basic experiments were conducted. The polishing parameters Sp. were obtained experimentally by changing the values of polishing process. Using polishing parameter, removal amount can be obtained and polished surface is possible to estimate.