Aluminium　alloy　material　has　become　hot　spot　in　building　structure　engineering　recently.　However,　the　study　on　the　local　buckling　behavior　of　aluminium　alloy　beams　awaits　in-depth　studies.　Although　China　has　GB　50429-2007　＇Code　for　design　of　aluminium　structures＇,　the　code　is　based　on　the　aluminium　alloy　specimens　of　small　section　and　thin-walled　specimens.　An　experimental　study　was　conducted　about　the　local　buckling　behavior　of　aluminium　alloy　I-shaped　beams　of　large　cross-section,　including　ten　specimens.　The　study　focused　on　the　failure　patterns　of　the　beams,　ultimate　loading　capacities,　load-deformation　curves　and　load-strain　curves.　And　a　finite　element　model　was　established　to　simulate　the　local　buckling　behavior　of　the　beams.　Six　specimens　occurred　compressive　local　buckling,　and　the　web　of　them　bulged;　four　of　them　occurred　shear　local　bulking,　and　tension　field　was　formed.　The　experimental　study　results　show　that　with　a　greater　width-to-thickness　ratio,　the　strength　of　the　material　is　more　wasted;　arranging　ribbed　stiffener　in　midspan　will　increase　the　ultimate　loading　capacities　greatly;　with　a　greater　height-to-thickness　ratio,　the　buckling　stress　will　be　lower,　and　there　will　be　a　greater　increase　in　the　post-buckling　strength;　and　the　results　of　finite　element　model　has　a　good　agreement　with　experimental　results.　©,　2015,　Science　Press.　All　right　reserved.