In this paper, the effect of top heave motion frequency on the global dynamic responses of a deep sea mining system is presented. The excitation of different frequencies is induced by time-varying heave motion of the surface vessel. First the numerical model of the system is established which can be solved by the lump mass method. Then three different scenarios caused by harmonic heave motion corresponding to different heave motion frequencies are introduced. On these basis, the pipe tension at bottom, deflection and bending force of the system are presented and discussed. Amplitude spectrum through FFT and the phase plots for the time histories of pipe bottom motion are made to analysis the possible different motion modes.