Considering　the　impact　of　post-earthquake　fire　on　building　structures　in　structure　design,　an　analysis　method　is　proposed　to　analyze　and　simulate　the　response　of　building　structures　under　post-earthquake　fire.　Based　on　the　seismic　response　and　thermal　stress　analysis,　this　method　considers　the　structure　seismic　damage　through　a　simplified　seismic　damage　model,　and　the　simulation　of　the　response　of　building　structures　under　post-earthquake　fire　was　reached　by　linking　the　heat　transfer　analysis　and　thermal　stress　analysis　to　the　results　of　seismic　damage.　A　single-storey　concrete　frame　and　a　multi-story　concrete　frame　were　analyzed　with　this　method　and　compared　with　experimental　results　of　the　same　concrete　frame　under　fire　without　seismic　damage.　It　is　shown　that　the　collapse　mode　may　change　for　seismic　damaged　structures　and　the　fire　resistance　decreases　with　the　increasing　of　seismic　damage　degree.