Abstract: The multiple tuned mass dampers(MTMD)consist of a group of single tuned mass damper(STMD)and the frequencies of the STMD group are distributed around the frequency of the controlled mode of the structure. The MTMD can overcome the disadvantage of instability of the control effect of the STMD and can enlarge the controllable frequency range of the STMD. The characteristics of frequency response of the multiple degrees structures with appending MTMD are studied. The time-history responses of the MTMD system excited by seismic waves under different site conditions are calculated. The theoretic analysis and simulating results show that the MTMD system can enlarge the applicable scope of seismic control of the STMD system and enhance the robustness of the control effect. It is concluded that the design of the MTMD system must take into consideration of the influence of the site conditions and the optimal selection of the parameters of the MTMD system must take into consideration of the specific conditions of the structure.