In cylindrical plunge grinding, a series of workpieces are ground successively without intermediate dressing of the wheel. Through the grinding, the wheel characteristic is continuously changed by the wear, fracture and new exposure of abrasive grains, having a profound effect on the grains on wheel surfaces in the cylindrical grinding process are developed to make it possible to describe the time dependent results of grinding and to establish the grinding operation standards capable of estimating grinding wheel performance and selecting grinding conditions, in which many parameters in actual grinding operations are considered. This simulation system can display its results in graphical form including the time dependent results and the effects of various parameters as well as optimization capabilities. This simulation has the same effects as many grinding experiments, and capable of selecting the optimum grinding wheels and conditions.