Tuned mass damper (TMD) and tuned liquid damper (TLD) have been reported to be feasible for motion control of offshore wind turbines. In this paper, we numerically investigate the performance of the hybrid TMD + TLD system on the motion reduction of a structure. The dynamic response of the structure can be notably suppressed when the optimal tuned frequency and damping of TMD are chosen. The addition of TLD would further reduce the motion of the structure when the natural frequency of the liquid tank is tuned to the external forcing frequency. The hybrid system can increase the bandwidth of excitation frequency to have low amplification factor of the structure. The sensitivity tests show the performance of the hybrid TLD + TMD system is related to the proper selection of mass ratio of TMD, depth ratio of TLD and damping coefficient of TMD. For practical engineering applications, a suitable parameters setting is suggested. Hybrid TMD + TLD system can also be applied to motion control of floating offshore structures in the near future.