A wind power generating system that is a technology for converting wind energy to electrical energy is provided. The system blocks flow of air inside the impeller, so that a high speed jet pressure on an I.G.V. (inlet guide vane) is converted to a constant pressure between the blades disposed downstream of the flow which has passed through the inlet guide vane, a vane pressure surface flows at high speed, thus generating relative retrograde pressure. In order to apply the pressure to the generation of torque, the inlet guide vane is as short as possible, the channel bends properly, and the inlet angle from the upstream to the downstream in a predetermined wing end speed ratio of the outlet angle has a most proper distribution. The wind power generating system has a higher power coefficient than a horizontal axis wind power generator, generates no noise to the surrounding environment when mounted, has smaller land compensation problems, and can be transported by land when a large capacity is available.