To　evaluate　the　extent　of　damage　and　level　of　energy　dissipation　of　high-rise　RC　base　isolation　structures　with　moment　resisting　frame　system　(MRFS)　and　shear-wall　frame　system　(SWFS),　nonlinear　inelastic　time　history　response　analysis　was　carried　out　under　horizontal　dual-component　earthquake　input.　Four　types　of　earthquake　input　were　derived　when　dual　components　were　switched　for　two　records,　the　original　record　and　a　new　record　obtained　from　decomposition　of　the　original　record　in　the　direction　of　the　maximum　amplitude.　A　potentially　useful　damage　index　was　established,　and　an　index　of　performance　evaluation　of　base-isolation　was　proposed　as　the　period-enhancement　factor.　Results　show　that　varying　decomposition-angle　of　the　original　record　has　little　influence　on　energy　response,　but　appreciable　on　damage　distribution,　and　that　input　of　the　new　record　might　not　correspond　to　the　most　serious　damage　and　the　largest　energy　dissipation.　For　the　SWFS,　the　first　story　has　the　largest　energy　dissipation　compared　with　other　stories,　while　the　MRFS　exhibits　better　energy-dissipation　and　a　near-trapezoid　distribution.　Generally,　structural　energy　response　is　mainly　influenced　by　the　input　record,　with　similar　trend　as　the　Arias　intensity　curve.