Site　condition　is　one　of　the　key　factors　affecting　the　seismic　response　of　underground　structures.　The　influence　of　site　homogeneity　on　the　seismic　fragility　of　subway　station　underground　structures　was　studied.　Taking　a　two-story　two-span　subway　station　as　the　research　object,　a　two-dimensional　finite　element　analysis　model　considering　soil-structure　interaction　was　established　on　the　ABAQUS/Standard　software　platform.　The　IDA　method　was　used　to　calculate　the　seismic　response　of　the　structure　locating　in　the　layered　site　and　the　homogeneous　site　respectively.　The　inter-story　drift　ratio　was　selected　as　the　damage　measure　and　the　PGA　was　selected　as　the　earthquake　intensity　measure　for　building　the　seismic　fragility　curves　of　the　subway　station　structure.　The　results　show　that　the　mean　of　the　structure　response　in　the　layered　site　is　significantly　higher　than　that　in　the　homogeneous　site,　while　the　standard　deviation　of　the　two　sites　are　identical.　Under　the　excitation　of　the　ground　motion　records,　the　failure　probability　of　the　structure　locating　in　the　layered　site　is　significantly　higher　than　that　in　the　homogeneous　site,　which　is　mainly　due　to　the　large　shear　deformation　of　the　soil　adjacent　to　the　structure　in　the　layered　site.　The　finding　provides　a　scientific　reference　for　the　performance-based　seismic　design　of　underground　structures.　©　2024　Chinese　Vibration　Engineering　Society.　All　rights　reserved.