The　paper　describes　a　study　on　the　effect　of　concrete　filled　chord　in　rectangular　hollow　section　(RHS)　and　circular　hollow　section　(CHS)　steel　tube　truss.　Tests　on　trusses　made　with　RHS　and　CHS　steel　tube　with　three　types　were　carried　out,　with　the　first　type　specimens　being　RHS　and　CHS　trusses,　the　second　type　specimens　being　RHS　and　CHS　trusses　with　concrete　filled　in　the　compressive　chord,　and　the　third　type　specimens　being　RHS　and　CHS　trusses　with　concrete　filled　in　both　the　compressive　and　the　tension　chords.　Test　results　indicated　that　all　rectangular　section　truss　specimens　failed　in　the　joints.　The　failure　of　RHS　truss　was　due　to　the　compressive　chord　plastification,　the　other　two　were　due　to　the　flange　punching　failure　mode　of　tension　chord　wall　which　connected　with　the　tension　branch.　The　CHS　truss　and　CHS　truss　with　compressive　chord　concrete-inside　failed　due　to　the　chord　plastification,　while　the　failure　of　the　CHS　truss　with　both　chord　concrete-inside　was　due　to　the　tension　brace　broken.　Concrete-filled　in　chord　can　not　only　help　reinforcing　steel　tube,　but　also　enhance　the　strength　and　rigidity　of　the　joints,　resulting　in　the　increase　of　the　ultimate　bearing　capacity　of　the　whole　trusses.　The　bearing　capacity　of　test　results　is　lager　than　the　calculations　according　to　corresponding　specifications.　The　impact　of　the　joints　deformation　should　be　taken　into　account　when　truss　deformation　is　calculated,　or　the　calculations　results　could　be　unsafe.　RHS　and　CHS　trusses　have　not　much　difference　in　the　load　bearing　capacity　and　deformation,　but　with　chord　filled　with　concrete,　the　CHS　trusses　have　the　higher　capacity　of　the　overall　truss　and　joints,　better　deformability　than　the　corresponding　RHS　trusses.