Based　on　lumped　mass　model　of　soil-structure　dynamic　interaction　system　proposed　by　Penzien,　a　simplified　method　of　soil-underground　structure　dynamic　interaction　system　is　constructed　with　the　consideration　of　the　shear　stiffness　and　damping　characteristic　of　equivalent　soil　layers.　Shifang　Bajiao　acceleration　record,　Songpan　acceleration　record　of　Wenchuan　earthquake,　China　in　2008　and　a　Taft　earthquake　acceleration　record　with　different　frequency　spectrum　characteristics　are　selected　as　bedrock　ground　motions;　then　the　simplified　method　and　2D　finite　element　method　are　employed　to　analyse　seismic　responses　of　soil-subway　station　structure　system.　The　results　indicate　that　the　peak　value　of　acceleration　response　of　subway　station　structure　of　the　simplified　method　is　more　than　those　of　2D　finite　element　method,　and　the　difference　degree　is　related　to　the　bedrock　ground　motion　characteristics.　With　the　peak　value　of　bedrock　ground　motion　increasing,　the　difference　degree　of　the　results　obtained　by　two　methodes　is　increasing;　but　the　general　law　is　consistent.　The　simplified　method　is　a　good　analysis　method　to　analyse　the　effect　of　soil-underground　structure　dynamic　interaction;　and　it　can　serve　as　a　auxiliary　method　for　aseismic　design　of　underground　structure.