Increasing　numbers　of　complex　structure　systems　with　underground　structures　crossing　a　cluster　of　aboveground　structures　are　being　constructed　in　densely　populated　urban　areas.　The　complex　dynamic　interaction　between　the　underground　structure,　aboveground　structure,　and　the　surrounding　soil,　is　called　structure-soil-structure　interaction　(SSSI).　The　SSSI　effects　bring　challenges　to　the　seismic　design　of　such　complex　structure　systems.　This　study　aims　to　analyze　the　influence　of　adjacent　aboveground　and　underground　structures　on　seismic　response　and　seismic　migration　performance　of　building　structures　using　dynamic　finite　element　simulations.　The　direct　method　is　used　to　establish　structures　and　soil.　A　comprehensive　numerical　analysis　is　first　presented　to　study　the　impact　of　adjacent　aboveground　and　underground　structures　on　target　building　structures　by　varying　the　distance,　form,　and　size　of　adjacent　structures,　etc.　Then,　the　seismic　migration　performance　of　building　structures　equipped　with　the　tuned　mass　damper　(TMD)　is　investigated.　The　numerical　results　indicate　that　the　presence　of　adjacent　aboveground　structures　has　a　limited　impact　on　the　seismic　response　of　the　target　structure.　The　seismic　response　of　the　target　structure　is　significantly　affected　by　the　adjacent　underground　structures.　The　TMD　designed　according　to　the　traditional　method　may　be　detuned　when　the　SSI　effect　is　significant.　The　TMD　performance　is　improved　by　considering　the　adjacent　structures.