The　seismic　resilience　of　underground　structures　is　one　of　the　critical　issues　for　the　development　of　resilient　cities.　However,　existing　assessing　methods　for　assessing　the　seismic　resilience　of　underground　structures　do　not　comprehensively　address　their　seismic　capacity　and　post-earthquake　recoverability.　This　paper　developed　a　seismic　resilience　index　and　framework　for　assessing　the　seismic　resilience　of　underground　frame　structures　by　considering　both　the　damage　and　functionality　of　underground　structures　caused　by　earthquakes,　as　well　as　the　processes　involved　in　repairs.　The　seismic　resilience　index　was　developed　by　quantifying　the　resist　resilience　and　recovery　resilience,　which　can　be　used　to　describe　the　robustness,　redundancy,　and　resourcefulness　of　the　seismic　resilience.　Then　the　assessing　procedure　for　this　method　is　presented　step　by　step.　Additionally,　a　case　study　was　conducted　to　assess　the　seismic　resilience　of　a　frame　subway　station,　focusing　on　the　economic　losses　associated　with　earthquakes.　The　study　also　discusses　the　improvements　in　seismic　resilience　achieved　through　the　use　of　reinforced　concrete　truncated　(RCT)　columns.　Results　indicate　that　RCT　columns　can　significantly　enhance　the　seismic　resilience　of　underground　structures.　The　reasonability　and　quantifiability　of　the　developed　method　were　compared　with　existing　methods,　demonstrating　its　effectiveness.　Furthermore,　the　developed　assessing　method　can　be　extended　to　assess　the　seismic　resilience　of　underground　structures　after　quantifying　their　operational　functionality.　©　2025　Elsevier　Ltd