Abstract: In this paper, an explicit integration formula of the dynamic model of elastic lumped-mass structures with damping is derived based on finite element discretization in time domain and its stability condition is also analyzed. It is shown that the numerical stability condition of the integration formula is same as that of the central difference method. This method can be conveniently used for calculating the dynamic response of structures with damping and large DOFs. Moreover, the shortcomings of the method combining central difference with single side difference are analyzed, and the calculation results of the proposal method are compared with analytical results and the results by the central difference with single side difference. It is shown that the accuracy of the proposed method is obviously higher than that of the central difference with single side difference.