Using　the　finite　element　program　ABAQUS/Standard　6.4,　theoretical　model　was　built　to　analyze　the　load　versus　deformation　curves　for　concrete　filled　circular　hollow　section　(CHS)　stub　columns　after　exposure　to　ISO-834　standard　fire.　The　numerical　results　show　good　agreement　with　the　test　results　reported　in　the　literature.　Furthermore,　the　stress　distributions　in　the　core　concrete　during　the　loading,　and　the　composite　interaction　between　the　steel　tube　and　the　concrete　were　studied　with　an　aim　to　clarify　to　influences　of　fire　exposure.　Based　on　the　analysis,　the　mechanisms　of　concrete　filled　CHS　stub　columns　after　exposure　to　fire　was　investigated.