A　theoretical　analysis　approach　of　the　compound　seismic　isolation　system　consisting　of　DFPS　and　dish　spring　is　derived.　It　starts　from　the　relative　kinematic　energy　theorem　in　multiply-body　dynamics,　including　the　coupling　effect　of　the　level　vibration　and　vertical　vibration.　Computation　results　show　that　this　system　has　the　necessary　isolation　capability　and　reposition　capability　in　both　directions;　the　slipping　friction　forces　at　the　contacting　surface　provide　the　energy　dissipation　capability.　When　the　slide　radius　is　in　the　range　of　1-2　m　and　the　slipping　friction　coefficient　is　about　0.01,　the　seismic　isolation　effectiveness　can　be　as　high　as　85%,　while　the　coupling　effect　in　two　directions　is　so　slight　that　it　can　be　neglected　and　the　dynamic　responses　can　be　calculated　in　each　direction,　respectively.