The dynamic response of a suspended cable subjected to a harmonic excitation was investigated.Based on the assumption of quasi-static stretching due to the fact that the transverse wave speed is much lower than the longitudinal wave speed,the nonlinear governing in-plane equation of the suspended cable was derived by means of Hamilton principle,which took into account the geometric nonlinearity of the suspended cable.And the displacement of the suspended cable was expanded in a series of the natural modes of the suspended cable.Then,the Galerkin method was used to obtain a finite-dimensional dynamical system.The periodic motions of the suspended cable were examined by means of the shooting method and the continuation method,while the non-periodic motions were studied through direct simulations.A comparison with the direct numerical results was performed.At last,the effects of the amplitude of the harmonic excitation on the periodic motion of the suspended cable were investigated.