If concrete filled steel tubes are used for structural member, it is increased in load carrying capacity and plastic deformation capacity by reciprocal confine of steel tube and concrete, and have an advantage to increase fire-resistance properties and to confine local buckling of steel tube. Especially these members have to superior in structural properties than the other section type, when used to compressive members. Accordingly, this study investigated to properties of structural behaviors through a series of experiment with the key parameter, such as diameter-to-thickness(D/t) ratio, slenderness ratio, loading condition and strength of concrete. The obtained results are summarised as follow. (1) The fracture mode of concrete filled steel tube column was presented fracture mode by compression failure at the end of specimens in stub column, but the fracture mode of long column was assumed an aspect of bending fracture transversely no relation with loading condition. Also, the restraint effect of concrete by steel tube was presented significantly in case of the loading condition the simple confined concrete by steel tube. (2) The concrete filled steel tube column was presented very excellent in deformation capacity and ultimate strength, compared with those of non-confined concrete. (3) The emprical formula to predict the ultimate capacity of confined concrete by steel tube and concrete filled steel tube column using restraint coefficient of concrete were proposed.