In　order　to　achieve　the　purpose　of　isolation　design　and　examine　the　performance　of　isolation　layer,　dynamic　properties　are　tested　and　analyzed　for　a　five-story　frame-structure　on　which　the　first-floor　isolation　technology　is　applied　under　environmental　vibration　and　different　initial　displacements　of　isolation　layer.　The　structure　s　first　three　natural　vibration　characteristics　including　frequencies,　mode　shapes　and　damping　ratios　are　obtained.　Hysteresis　curves　and　free　damping　curves　under　different　initial　displacements　of　isolation　layer　are　drew　and　analyzed.　Test　and　analysis　results　indicate　that　the　isolated　structure　and　the　un-isolated　structure　have　similar　dynamic　properties　under　environmental　vibration,　and　the　isolated　structure　with　full　hysteresis　loops　has　adequate　stability　longer　period　and　higher　damping　ratios　than　un-isolated　structure.　Isolation　layer　has　obvious　property　of　resetting,　which　answers　the　long-term　question　whether　the　isolation　layer　has　the　property　of　resetting.