Bending　of　concrete　filled　steel　tubular　(CFST)　dumbbell-shaped　beams　is　studied　experimentally.　Two　types　of　cross　sections　of　beams　are　discussed.　One　is　the　traditional　type　with　concrete-filled　in　the　web　space,　the　other　is　a　new　type　without　concrete　in　it.　Experimental　results　show　that　the　CFST　dumbbell-shaped　beam　has　favorable　elastoplastic　and　ductile　properties.　It　can　bear　load　even　when　the　deflection　reaches　one-twentieth　of　its　span.　The　concrete　in　the　steel　web　has　some　influence　on　the　local　behavior　of　the　web,　but　has　very　small　influence　on　the　overall　behavior　of　the　beam.