The aim of this study is to obtain the optimum set of dressing parameters which can generate minimum surface roughness when carrying grinding process of SKD11 hardened steel by CBN grinding wheel. The selected input parameters are dressing depth, dressing feed rate and dressing spindle. The optimization process is validated by experiments planned to be tested by using Taguchi method. It is found that the dressing depth has the largest effect on the surface roughness, and the influential percentage is 74.37%. Followed are the influences of the dressing feed rate and the dressing spindle speed with 13.07% and 6.28%, respectively. Additionally, it is revealed that the differences between the experiments and the predictions are minor when showing the deviation of 8.06%. The experimental results showed that it is possible to employ Taguchi method to study experiments and predictions in case of grinding SKD11 hardened steel by CBN grinding wheel.