The　paper　deals　with　an　experimental　investigation　of　stocky　reinforced　concrete　(RC)　columns　confined　by　stirrups　with　a　slenderness　ratio　of　3.　A　total　of　24　columns　were　designed　and　tested.　In　the　tests,　the　confining　action　and　the　size　effect　for　the　columns　with　circular　and　square　cross　sections　were　studied,　and　the　effects　of　stirrup　ratio　and　concrete　cover　were　also　explored.　The　maximum　structural　sizes　for　the　circular　and　squared　columns　were　respectively　576　mm　in　diameter　and　600　mm　in　cross-sectional　width.　The　test　observations　indicate　that,　increasing　the　stirrup　ratio　could　make　the　enhancement　of　the　nominal　strength　and　improvement　of　ductility　capacity.　At　the　same　stirrup　ratios　and　cross-sectional　sizes,　both　the　nominal　strength　of　the　circular　columns　is　higher　and　the　deformation　capacity　is　larger　than　those　of　the　square　columns.　Overall,　the　failure　of　the　RC　columns　with　a　lower　stirrup　ratio,　without　cover　and　having　square　cross　section　is　more　brittle,　exhibiting　a　stronger　size　effect.　In　addition,　the　nominal　compressive　strengths　of　all　the　tested　columns　are　in　good　agreement　with　the　size　effect　law　(SEL)　proposed　by　Bazant.