Experimental　study　and　numerical　analysis　were　completed　on　a　high-rise　isolated　steel　frame　model　with　aspect　ratios　5　and　2.5.　The　experiment　results　show　that　the　high-rise　isolated　structure　with　small　or　large　aspect　ratio　are　of　good　isolation　effect　under　earthquake.　The　shear　deformation　usually　occurs　alone　on　the　small　aspect　ratio　isolation　structure,　while　the　bend　and　shear　deformation　will　occur　simultaneously　on　the　large　aspect　ration　isolation　structure.　The　bend　and　shear　deformation　of　superstructure　should　be　considered　in　the　design　of　large　aspect　ratio　high-rise　isolated　structure　and　super　high-rise　isolated　structure.