With the development of wind power generation, the vibration and noise become a serious problem. The wind turbine blade has unique characteristics that long large blades rotate in a verticl plane under the action of gravity. Because the velocity of the wind is different between at low and high positions, a periodic excitation force works to the blades. In addition, a pulse works to the blade when the blade passes near the pole. In this research, the blade is modeled by a rotating elastic cantilever beam. It is clarified that various kinds of resonances occur. Their vibration characteristics are clarified by the simulation.