The　optimal　index　of　earthquake　intensity　measures　required　in　the　probabilistic　seismic　demand　model　for　seismic　design　of　the　underground　frame　structure　of　shallow-buried　subway　station　is　studied.　Based　on　the　ABAQUS/Standard　platform,　the　two-dimension　model　for　an　underground　frame　structure　is　established.　The　seismic　responses　of　three　subway　station　cross-sections　are　obtained　by　using　the　nonlinear　dynamic　time-history　analysis　in　term　of　22　far-field　earthquake　records.　The　peaks　of　inter-story　drift　ratios　are　obtained　and　selected　as　the　structural　damage　measure,　and　15　candidate　intensity　measures　(IMs)　are　examined　based　on　the　characteristics　of　efficiency,　practicality,　proficiency　and　sufficiency.　The　results　show　that　PGA　is　an　optimal　IM　for　the　probabilistic　seismic　demand　model　for　the　underground　frame　structure　of　shallow-buried　subway　station,　whereas　the　PGV　or　the　velocity　response　spectrum　is　an　alternative　IM.　However,　the　PGD,　root-square　of　displacement,　root-mean-square　of　velocity　and　root-mean-square　of　displacement　are　failed　in　the　tests　on　the　sufficiency,　in　which　they　are　not　appropriate　to　the　probabilistic　seismic　demand　analysis　for　the　underground　frame　structure　of　shallow-buried　subway　station.　The　findings　may　provide　a　helpful　guide　to　the　performance-based　seismic　design　of　underground　structure　and　to　the　developing　and　improving　of　the　determination　method　of　optimal　IMs　of　the　existing　probabilistic　seismic　demand　model　for　shallow-buried　underground　structure.　©　2023　Chinese　Society　of　Civil　Engineering.　All　rights　reserved.