The　influence　of　velocity　pulse　characteristics　of　near-fault　ground　motions　on　the　seismic　response　of　base-isolated　structures　was　investigated　in　this　paper.　The　analysis　models　of　traditional　seismic　frame　structures　and　corresponding　base-isolated　structures　with　different　height-to-width　ratios　were　established　by　using　finite　element　software.　Six　ground　motion　records　with　forward　directivity　velocity　pulse　and　fling　step　velocity　pulse　were　selected　as　the　seismic　input　at　foundation　of　structures,　and　eight　structures　were　analyzed　by　nonlinear　dynamic　time-history　analysis.　The　comparative　analysis　is　carried　out　on　parameters　of　the　structure　responses　such　as　the　inter-story　drifts,　bearing　displacement　and　base　shear　force.　Under　the　velocity　pulse-like　ground　motions,　the　inter-story　drifts　and　the　base　shear　of　base-isolated　structures　gradually　increase　when　the　height-to-width　ratio　increases　but　the　displacements　tend　to　increase　first　and　then　decrease,　and　the　displacement　of　isolation　layer　increases　with　the　ratio　of　peak　velocity　to　peak　acceleration　of　the　input　ground　motions.　The　base-isolated　structures　with　the　height-to-width　ratio　less　than　3　have　better　vibration　reduction　capacity　under　velocity　pulse-like　ground　motions.　The　smaller　the　height-to-width,　the　better　the　vibration　reducing　effect,　and　conversely,　the　seismic　capacity　of　base-isolated　structures　is　poor　if　the　height-to-width　ratio　of　the　structure　is　4.The　adverse　effect　of　velocity　pulse　of　near-fault　ground　motion　on　the　response　of　lower　part　of　the　base-isolated　structure　may　even　lead　to　collapse　damage　on　the　structure.　©　2018,　Editorial　Office　of　Journal　of　Building　Structures.　All　right　reserved.