Experimental　research　on　CFST　dumbbell-shaped　columns　with　initial　stresses　subjected　to　axial　loads　are　carried　out.　Influence　of　initial　stress　to　the　behaviors　and　ultimate　load-carrying　capacity　are　discussed.　Analytical　results　indicate　that　initial　stress　make　the　elastic-plastic　phase　ahead,　the　tangent　rigid　and　elastic　ultimate　load　decreased.　However,　the　ultimate　load　almost　doesn＇t　be　influenced　by　the　initial　stress　and　can　be　predicted　by　the　method　used　in　a　CFST　dumbbell-shaped　stub　without　initial　stress.