The　spatial　variability　of　soil　elastic　modulus　not　only　affects　the　characteristics　of　input　seismic　waves　but　also　increases　the　randomness　of　structure　dynamic　response　and　affects　the　reliability　of　structure　in　terms　of　considering　the　SSI　effect.　In　order　to　explore　the　influence　of　the　spatially　variable　soil　elastic　modulus　on　the　seismic　response　of　isolated　structures，the　random　field　simulation　technology　is　combined　with　finite　element　analysis　to　conduct　the　dynamic　＇non-intrusive＇　random　finite　element　calcula⁃　tion　based　on　Monte　Carlo　Simulation.　Taking　the　shaking　table　test　of　a　typical　large　chassis　isolation　structure　as　an　example，the　deterministic　and　random　finite　element　analyses　are　carried　out.　The　relevant　response　parameters　of　the　structure　are　calculated，and　the　AIC　value　is　used　to　determine　the　best-fit　marginal　distribution　of　the　response　parameters.　The　results　reveal　that　when　the　spatial　variability　of　soil　is　considered，the　amplification　effect　of　non-homogeneous　soft　soil　on　the　amplitude　of　the　low-fre⁃　quency　seismic　wave　is　more　obvious　than　that　of　homogeneous　soft　soil.　The　peak　value　of　the　Fourier　spectrum　increases　by　about　14.2%　and　the　distribution　of　spectral　value　concentrates　to　low-frequency.　The　deterministic　analysis　underestimates　the　am⁃　plification　impacts　of　SSI　effects　on　the　acceleration　of　the　isolation　layer　and　the　displacement　response　of　floors　above　the　isolation　layer.　According　to　the　AIC　value，it　is　not　always　reliable　to　use　normal　or　lognormal　distribution　to　describe　the　distribution　of　da⁃　ta.　It　needs　to　determine　the　best-fit　marginal　distribution　of　response　parameters，so　as　to　provide　a　more　reasonable　design　basis　for　structural　isolation.　©　2023　Nanjing　University　of　Aeronautics　an　Astronautics.　All　rights　reserved.