Headed　studs　attached　to　the　internal　face　of　the　steel　tube　of　concrete-filled　steel　tubular(CFST)　components　enhance　the　composite　effect　between　steel　tube　and　core　concrete.　Testing　of　8　CFST　specimens　with　headed　studs　was　conducted,　considering　the　primary　variables　core　concrete　strength,　diameter　and　length　of　headed　studs,　and　the　results　compared　with　1　CFST　specimen　without　headed　studs　and　4　composite　beam　specimens　with　headed　studs.　The　results　show　that　the　load-slip　curve　of　a　CFST　specimen　with　headed　studs　consists　of　a　linear　elastic　stage,　an　elastic-plastic　stage,　a　load　descent　stage,　and　a　load　residual　stage.　The　headed　studs　were　sheared　off　at　the　peak　load　while　no　fracture　or　crushing　of　concrete　had　occurred　and　the　stress　in　the　steel　tube　was　very　low.　The　ultimate　load　of　CFST　specimens　with　headed　studs　were　673.3　kN~1356.9　kN,　much　higher　than　the　85.7　kN　of　the　specimen　S4-1　without　headed　studs,　which　shows　the　obvious　improvement　from　the　headed　stud　on　the　composite　action　of　the　steel　tube　and　core　concrete　after　debonding　between　them.　No　separation　between　core　concrete　and　steel　tube　was　observed　in　the　test　of　the　CFST　specimens　with　headed　studs,　which　resulted　full　utilization　of　the　headed　studs　and　1.69~1.73　times　as　much　ultimate　bearing　capacity　as　the　composite　beam　specimens　with　headed　studs.　The　shear-bearing　capacity　of　headed　studs　in　CFST　increases　with　increasing　core　concrete　strength　and　stud　diameter,　but　it　is　little　affected　by　stud　length.　Based　on　the　analysis　on　experimental　results,　a　formula　to　predict　the　shear-bearing　capacity　of　headed　studs　in　CFST　is　proposed.　©　2016,　Engineering　Mechanics　Press.　All　right　reserved.