Abstract: Based on the dynamic response and permanent deformation of high core rockfill dams, the seismic reinforcement measures and efficiencies are studied. The ultimate aseismic capacity of a reinforced dam is evaluated. The results show that the elasto-plastic dynamic method is feasible for the analysis of high core rockfill dams. The greater the seismic intensity, the greater the dynamic shear stresses and dynamic shear strain within the dam, the greater the dynamic response and the permanent deformation of the dam. The settlement is larger than the horizontal displacement under earthquakes. The main form of earthquake deformation is settlement. The large deformation zone is the upper scope (1/5) of the dam and valleys corresponding to the top of the dam site. The vertical displacement is significantly lower by using the reinforcement measures. From the preliminary evaluation of stability and deformation the reinforcement ultimate aseismic capacity of the dam is improved 0.05gthan that of the original dam.