The purpose of this investigation is to clarify the effects of the splitter plate in the wake of a bluff body. The base pressure of a body that generates the wake and the fluctuating velocity vector in the wake were measured under the many conditions of plate location and width. As the result of this study, it was found that the base pressure and the Reynolds shear stress can be controlled by the splitter plate, and there is an optimum condition to reduce the drag of a body and to increase the Reynolds shear stress in the wake.