In　order　to　reveal　the　size　effect　law　of　high　strength　concrete　columns,　axial　compression　experiments　of　high-strength　concrete　columns　with　different　geometric　dimensions　and　no　stirrups　were　carried　out.　Based　on　the　experiment　results,　failure　characteristic,　stress-strain　curve,　maximum　carrying-load　capacity,　deformation　capacity　and　stiffness　of　specimens　with　various　dimensions　were　comparatively　analyzed.　The　results　show　that　as　to　high　strength　concrete　columns　without　stirrups　under　axial　loading,　size　effect　exists　in　failure　characteristic,　maximum　carrying-load　capacity　and　deformation　capacity,　but　not　in　stiffness　degradation.