The compressive strengths of simply supported columns may be significantly increased by reinforcing them with an assemblage of cross-arms and stayed struts connecting both ends of the columns and the cross-arm members. The purpose of the stayed struts and cross-arms is to introduce partial restraints against translation and rotation, thereby decreasing the effective buckling length of the column. In this study, buckling strengths of the assembled column system have been quantitatively evaluated from the theoretical methods based on both the equivalent spring model and the stiffness matrix formulation. And the results were compared with those from elastic/inelastic analysis using a finite element analysis package program, ABAQUS, for verification purpose. Expected compressive strength curves have been proposed for the assembled column system as a function of slenderness ratio of the simply supported column.