Abstract: Dynamic characteristics of a large crossing transmission tower-line system (LCTTL) are analyzed.The seismic responses of a large crossing transmission tower-line system subjected to near-fault pulse-like ground motions and ordinary ground motions are compared.The characteristics of responses caused by near-fault pulse-like ground motions are presented.It is shown that the seismic responses of LCTL induced by near-fault pulse-like ground motions are severer than the responses subjected to ordinary ground motions.The amplitude of seismic responses increases with the pulse period of near-fault pulse-like ground motions.An equivalent pulse model is introduced to seismic response evaluation of LCTL.The results demonstrate that the equivalent pulse model can capture the important response characteristics of the near-fault records.The application of equivalent pulse model in seismic responses analysis of LCTL can augment the number of near-fault record set.