To　study　the　post-impact　seismic　behavior　of　circular　steel　tubular　columns,　quasi-static　tests　were　carried　out　on　twelve　circular　steel　tubular　columns　after　being　subjected　to　impacts　and　three　columns　without　being　subjected　to　impacts.　The　effects　of　impact　height　and　axial　compression　ratio　on　the　failure　modes,　hysteretic　behavior,　ductility,　stiffness　degradation　and　energy　dissipation　of　the　specimens　were　investigated.　Based　on　the　quasi-static　tests,　a　restoring　force　model　considering　the　effects　of　impact　height　and　axial　compression　ratio　was　established.　The　research　results　indicate　that　both　the　impact　height　and　axial　compression　ratio　have　significant　effects　on　the　hysteretic　behavior　of　the　specimens.　With　the　increase　of　impact　height,　the　hysteretic　curves　gradually　change　from　full　and　symmetric　spindle　shape　to　narrow　and　asymmetric　spindle　shape,　and　the　ultimate　capacity　and　deformation　capacity　of　the　specimens　decrease　gradually,　while　the　ductility　and　cumulative　energy　dissipation　reduce　remarkably.　With　the　increase　of　axial　compression　ratio,　the　fullness　of　the　hysteretic　curves　decreases　evidently,　the　ultimate　capacity　and　ultimate　deformation　of　specimens　decrease,　and　the　ductility　and　cumulative　energy　dissipation　deteriorate　remarkably.　The　calculation　results　of　the　restoring　force　model　for　circular　steel　tubular　columns　after　being　subjected　to　impact　are　in　good　agreement　with　the　test　data,　so　the　proposed　model　can　be　used　for　the　seismic　elastic-plastic　analysis　of　engineering　structures.　©　2022,　Editorial　Office　of　Journal　of　Building　Structures.　All　right　reserved.