A simple and efficient method of buckling/plastic collapse analysis of stiffened plates subjected to uni -axial thrust is presented. Plate part between stiffeners is divided into several plate elements in the stiffener direction. Thebuckling/plastic collapse behaviour of plate element is simulated using a simple dynamical model combining the results of elastic large deflection analysis and rigid plastic mechanism analysis. The influence of a torsional stiffness of stiffeners on the local buckling strength of plate part is taken into account. Stiffener part is modeled by beam-column elements which can simulate a flexural-torsional buckling behaviour of thin-walled beams. Coupling the plate and beamcolumn elements, the buckling/plastic collapse behaviour of stiffened plates accompanied by both local and overall buckling can be analysed. It is also possible to simulate a localisation of plastic deformation in a certain part of panel deflection and a resulting unloading in the remaining part, which have a large influence on the capacity beyond the ultimate strength. Using the proposed method, a series of buckling/plastic collapse analysis of stiffened plates is performed, and the applicability of the proposed method is discussed through a comparison with the ordinary elastoplastic large deflection FEM analysis.