Nuclear fusion may solve the energy crisis of human beings. For the magnetic confinement fusion, one of the most important research topics is the energetic particle driven instabilities, because these instabilities may enhance energetic particle transport and deteriorate confinement of plasmas. By using hybrid simulation code MEGA, both the linear and nonlinear properties of energetic particle driven instabilities can be investigated, and also, the mechanisms of various phenomena can be clarified. These works are helpful for further understanding of fusion plasma, and useful for confinement improvement.