This　paper　is　to　study　the　seismic　response　of　spatial　structure　incorporating　the　soil　structure　interaction　(SSI).　The　SSI　model　for　the　long-span　spatial　structure　with　supporting　substructure　is　proposed　and　the　relevant　soil　parameters　according　to　the　IBC　code　are　presented.　A　procedure　for　calculating　the　total　damping　ratios　for　one　DOF　system　is　used　in　the　seismic　analysis　of　spatial　structure　including　SSI.　The　displacement　and　the　axial　force　in　the　member　under　different　soil　conditions　are　compared　and　some　important　conclusions　are　drawn.