This　paper　presents　the　experimental　and　numerical　investigations　on　mechanical　behavior　of　I-section　steel　columns　after　elevated　temperature　exposure.　A　total　of　twenty-six　compression　tests　were　carried　out,　in　which　one　was　under　ambient　temperature　and　the　other　twenty-five　were　under　heating　and　cooling　phase　to　study　the　influence　of　high　temperature　(400,　550,　700,　850,　1000°C)　and　high　temperature　duration　(0.5,　1,　1.5,　2,　2.5 h)　on　mechanical　behavior　of　the　specimens.　The　failure　pattern,　axial　load　versus　strain　relation,　axial　load　versus　displacement　relation　and　ultimate　strength　of　the　specimens　were　presented　and　analyzed.　The　test　results　showed　that,　high　temperature　duration　had　limited　influence　on　the　ultimate　strength　and　other　mechanical　behaviors　of　the　specimens,　while　the　ultimate　strength　decreases　with　the　increase　of　the　maximum　temperature　the　specimens　suffered　and　some　other　behaviors　also　changed.　The　failure　pattern　of　specimens　after　high　temperature　did　not　change　compared　with　that　of　specimens　under　ambient　temperature.　The　finite　element　models　that　have　the　same　geometry　with　the　test　specimens　were　set　up　to　compare　with　the　test　specimens　and　the　results　predicted　from　finite　element　analysis　showed　good　agreement　with　that　measured　in　test.　Therefore,　parametric　study　was　carried　out　to　investigate　the　influence　of　different　section　geometry　on　the　ultimate　strength　of　I-section　steel　short　columns　after　elevated　temperature.　A　new　relationship　for　the　ultimate　strength　for　I-section　steel　short　columns　after　elevated　temperature　was　developed　and　proved　to　be　reliable　and　accurate.　What’s　more,　the　effect　of　slenderness　ratio　on　the　stability　coefficient　of　the　columns　was　also　investigated　in　the　parametric　study.　©　2018,　Springer　Science+Business　Media,　LLC,　part　of　Springer　Nature.