Based on experimentthatal results,we conclude that confinement in regional confined concrete(RCC) columns is more efficient than that in normal confined concrete(NCC) columns.As loads increase,NCC column sections tend to become round;the corner concrete in the core area may break;and,the strains of external stirrups tend to drop slightly after the peak load.RCC columns,however,remained thoroughly rectangular and the stirrup strain increased steadily.The failure mode of RCC columns was totally different from that of NCC columns.While NCC columns tended to fail in shear,followed b a rapid drop in load carrying capacity,the RCC columns developed gaps in their midsections and the columns separated into several slender columns.After a long deformation period,the RCC columns retained approximately 40% of their load carrying capacity.It can be expected that this characteristic may benefit the anti-seismic capacity of structures.