The　paper　presents　the　results　of　12　groups　of　geometrically　similar　reinforced　concrete　(RC)　squared　columns　subjected　to　the　combined　loading　of　compression　and　bending.　The　performances　and　characteristics　of　the　test　RC　columns　are　investigated　in　terms　of　the　capacity　of　dissipated　energy,　the　ductility　capacity,　the　flexural　capacity,　the　stiffness　degradation　as　well　as　the　rotation　capacity　of　plastic　hinge.　The　study　also　examines　the　influences　of　structural　size,　axial　load　ratio　and　the　loading　types　(involving　monotonic　and　cyclic　lateral　loading)　on　the　flexural　compressive　failure　characteristic　of　columns.　The　test　observations　indicate　that　the　failure　patterns　of　the　tested　columns　are　closely　similar　in　spite　of　the　difference　in　cross-sectional　dimensions,　and　the　flexural　compressive　failure　of　the　columns　presents　obvious　size　effect.　As　the　structural　size　of　the　tested　RC　columns　increases,　the　dimensionless　nominal　moments　(involving　the　nominal　yield　moment,　the　maximum　moment　and　the　ultimate　moment　corresponding　to　ultimate　displacement),　the　ultimate　drift　ratio,　the　displacement　ductility　and　the　rotation　capacity　of　plastic　hinge　decrease　significantly.　Moreover,　a　larger　axial　load　ratio　leads　to　larger　load　carrying　capacity　and　weaker　deformation　capacity.