In　this　paper,　a　comparative　study　of　the　seismic　response　and　fragility　of　a　station　structure　before　and　after　being　retrofitted　with　an　LNB　installed　on　the　top　of　its　columns　is　conducted　to　evaluate　the　effectiveness　of　retrofitting　measures　in　reducing　risk　probability　employing,　for　the　first　time,　a　probabilistic　approach.　The　Daikai　subway　station　was　adopted　as　a　case　study,　and　two-dimensional　finite　element　models　of　soil-structure　system　with　and　without　LNB　were　established.　Incremental　dynamic　analyses　(IDA)　of　original　and　retrofitted　structures　were　conducted　to　evaluate　their　seismic　responses　under　different　ground　motion　intensities　and　considering　the　uncertainty　of　ground　motion.　Further,　the　IDA　curve　cluster　and　quantile　lines　of　station　structure　and　rubber　bearing　were　constructed.　Finally,　the　seismic　fragility　curves　of　structure　and　LNB　were　established　for　the　risk　assessment　under　different　performance　levels　based　on　the　structural　performance　index.　The　results　demonstrated　that　the　horizontal　deformation,　shear　force　and　bending　moment　of　the　central　column　fitted　with　rubber　bearings　are　greatly　reduced　compared　with　the　actual　Daikai　station　structure,　which　is　more　pronounced　for　lower　ground　motion　intensity.　In　addition,　the　failure　probability　of　the　retrofitted　structure　corresponding　to　different　damage　levels　is　much　lower　than　that　of　the　original　structure　under　the　same　ground　motion　intensity.　Meanwhile,　the　probability　of　moderate　to　severe　damage　for　the　underground　station　structure　is　greatly　reduced　after　retrofitting　with　the　rubber　bearings.　The　overall　seismic　performance　of　the　structure　is　significantly　improved　and　post-earthquake　repair-demand　is　greatly　decreased.