Shaking　table　test　of　the　mega-sub　control　system　was　carried　out　in　order　to　study　the　seismic　performance　of　this　system.　Test　specimens　were　3　steel　frames,　called　aseismic　model,　isolated　model　and　isolated-bottom　consolidated　model,　respectively.　Nonlinear　dynamic　time　analyses　of　the　test　models　were　performed　using　SAP2000.　Theoretical　results　were　compared　with　the　experimental　results　on　some　structural　responses　including　the　acceleration　response　and　story　drift　response　of　the　mega-structure,　the　story　drift　response　of　the　substructure,　and　the　deformation　of　the　isolation　layer.　The　results　shows　that　theoretical　analysis　are　in　good　agreement　with　the　experimental　results.　The　structural　responses　of　the　isolated　model　and　isolated-bottom　consolidated　model　are　greatly　reduced　compared　with　that　of　the　aseismic　model,　which　can　be　illustrated　by　both　the　theoretical　results　and　experimental　results.　It　is　concluded　that　the　isolation　devices　can　reduce　the　structural　responses　effectively,　and　make　the　structure　safer　than　that　without　isolation　devices.　©　2016,　Engineering　Mechanics　Press.　All　right　reserved.