Based　on　a　prototype　of　a　Concrete　Filled　Steel　Tubular(CFST)　column　(D=1.2m,　t=24mm)　used　in　a　practical　engineering,　specimens　length-diameter　ratio　of　which　is　3:1　are　designed　to　conduct　the　uniaxial　compression　experiment　according　to　three　scales　which　are　1:2.4,　1:3.6　and　1:4.8.　FE　model　is　established　to　simulate　the　loading　process　by　means　of　finite　element　software　ABAQUS.　The　study　shows　that　the　bearing　capacity　of　test　is　much　higher　than　the　value　calculated　according　to　codes.　It＇s　about　7%　higher　than　the　design　bearing　capacity　calculated　according　to　code　CECE28:90.　The　outer　steel　tubes　of　CFST　columns　used　in　engineering　are　generally　processed　by　wrapping　and　welding.　The　welding　zone　is　easily　to　yield　firstly　when　the　CFST　columns　are　under　uniaxial　compression,　which　can　change　the　compression　bearing　state　of　the　cross　section　to　bias　compression.　As　a　result,　the　bearing　capacity　of　the　CFST　columns　would　decrease　to　some　extend.