Abstract: he aeroelastic stability of coupled flap-lag-torsion dynamics of rotor blades in hover is studied in this paper.According to Hamilton principle,nonlinear partial differential equations of motion for elastic flap bending and torsion of the blade are derived.The spatial dependence of the partial differential equations is discretized by use of the Galerkin finite element method.The effects of some structural parameters are taken into account,such as the collective pitch,precone,sweep,and so on.Finally,the aeroelastic stability of Dolphin's Rotor blades is analysed.The experiment shows that the aeroelastics stablity of the rotor blade in hover is influenced small by the blade sweep,but strongly by the collective pitch and precone.The experimental results verify the feasibility of the analysis and applicability to rotor design.