In　this　paper,　the　dynamical　analysis　model　of　story　isolation　structures　are　established.　Main　influential　parameters　of　story　isolation　structures　are　theoretically　investigated.　Results　indicate　that　within　the　scope　of　certain　frequency　ratio,　infrastructure　displacement　and　superstructure　acceleration　of　the　isolation　layer　both　significantly　reduce,　when　the　location　of　isolation　layers　is　approach　to　the　roof　of　the　structure.　Its　mechanism　is　similar　to　that　of　TMD　and　there　is　no　obvious　change　between　infrastructure　displacement　and　superstructure　acceleration,　when　the　location　of　the　isolation　layer　is　approach　to　the　base　of　the　structure.　Its　mechanism　is　similar　to　that　of　base　isolation.　Damping　ratio　of　isolation　layer　greatly　influences　the　isolating　effect.　When　the　damping　ratio　increases,　the　isolating　effect　is　better.