In　order　to　study　the　size　effect　of　reinforced　concrete　column　under　large-eccentric　loading,　the　test　is　carried　on　three　sets　of　different　rectangular　cross-section　columns　without　stirrups　in　middle,　which　are　200　mm　×　300　mm,　400　mm　×　600　mm,　600　mm　×　900　mm　respectively,　and　the　concrete　grade　is　C30.　The　paper　reveals　the　size　effect　law　by　studying　failure　characteristics,　cross　section　strain　distribution,　bearing　capacity　and　deformation　ability.