The purpose of this paper is to clarify the local buckling and the post local buckling behavior of H-section steel columns owing to the interaction of plate elements, from the view point of the width-thickness ratio and the area ratio of the plate elements. A series of stub-columns test is performed. The specimens are composed of thin plate and thick plate elements. The main parameters are the width-thickness ratio and the area ratio of plate elements. Following this test results, the evaluation formulas of the deformation capacity of H-section steel stub-columns considering the area ratio are proposed, and the evaluation formulas are compared with the test results.
