Flying beings by flapping wings show a hovering flight without stall because they can exploit vortices for their flight. The mechanism of the flapping wing flight makes clear, gradually. Therefore, it is considered that a flapping wing vehicle can be developed based on the mechanism with high efficiency rather than fixed-wing aircraft and rotary-wing aircraft in some situation. However, the flapping motion of flying beings is too complicated to reproduce completely. In this paper, flowfields around simplified flapping motion for the real flapping vehicle are investigated using CFD to make clear the relationship between vortices and unsteady fluid forces. Moreover, several motion parameters to develop the vertical takeoff and landing (VTOL) aircraft with flapping motion are discussed based on the actual equipment.