In the development of new large megawatt size wind turbines, aerodynamic and structural reserch is interesting and important for study wind turbine performace and boost the development of wind power. In this paper, the aerodynamic and aeroelastic characteristic of blades is investigated and presented based on Blade Element Momentum and Hamilton theory. Then the flexible characteristics of balde is researched with the aerodynamic and aeroelastic model of the rotor. The flapwise and edgewise displacements, velocities and accelerations of blade tip are simulated and plotted to validate the model which is presented in this paper. The results have very important significance to investigate the vibration and fatigue lifetime of the wind turbine blades.