The　seismic　mitigation　performance　of　a　metafoundation　with　soil-structure　interaction　was　investigated　utilizing　shaking　table　tests.　The　results　indicated　that　the　metafoundation＇s　performance　strongly　depended　on　the　coupling　among　the　frequencies　of　the　soil　layer,　structural　systems,　and　input　motions.　Due　to　resonant　effects,　the　response　of　the　controlled　structure　could　be　greater　than　that　of　the　uncontrolled　superstructure　at　small　input　PGAs.　By　contrast,　the　metafoundation　exhibited　excellent　mitigation　effects　at　large　PGAs.　A　simplified　elastic　model　was　validated　by　the　experimental　results.　Then　the　validated　model　contributed　to　the　interpretation　of　experimental　phenomena　based　on　equivalent　linear　parameters.