Abstract: To investigate the influence of local cable vibration on the seismic behavior of cable-stayed bridges,the analytical solutions of the first order natural frequency of inclined cables of a cable-stayed bridge were derived with considering the sag effect and the initial equilibrium state,and the FEM(finite element method) solutions of the natural frequency of inclined cables were obtained based on the multi-element cable model.The effect of local cable vibration on girder vibration was analyzed by inputting two kinds of seismic excitations with identical amplitudes but different spectrum properties.The research shows that the analytical solutions are identical with the FEM solutions,this means that the multi-element cable model can correctly reflect the vibration features of inclined cables.When low order vertical vibration mode frequencies of the girder are inconsistent with earthquake dominant frequencies,an additional damping effect on girder vibration will be caused;on the contrary,an amplificatory effect of vibration because of coupled vibration of cables and girder will be result in.