The objective of this study is to present an iterative momentum-time element for nonlinear dynamic analysis of structures. Based on the temporal discretization of time finite element approximation and the principle of momentum, the momentum-time element was developed. Since the moment-time element has an accuracy of fourth order, large time steps are allowed to compute dynamic response of nonlinear dynamic systems using the present algorithm. On the other hand, this technique requires only displacements and velocities to be made available at the start of the current time step for integration in state space, the errors caused by estimation of acceleration by previous finite-difference methods are circumvented. Moreover, using the momentum principle can smooth out the load discontinuity in a time interval so that the proposed momentum-time element is available to the problem of discontinuity caused by impulsive loads. To resolve the nonlinear dynamic system, an iterative procedure is included in the momentum-time element for each time step, involving the three phases of predictor, corrector, and error-checking. The effectiveness and robustness of the proposed algorithm in solving nonlinear dynamic problems is demonstrated in the numerical examples.