The author's research group developed Plastic Node Method (P. N. M.) and has demonstrated the efficiency of this method in analyzing the material nonlinear behavior of many kinds of structures, such as ships, offshore structures. While, for analysis of elastic large deflection (geometrical nonlinear behavior) of structural elements, such as beam-columns, rectangular plates, some analytical methods are effective. In this paper, these two methods are combined for an accurate and efficient analysis of elasto-plastic large deflection of these elements. The work of this paper will be summarized as follows. 1) The original plastic node method is modified in such a way that condensed nodal plastic displacements are redistributed in the element for evaluation of elasto-plastic stiffness with large deflection.By this treatment, an accurate analysis becomes possible for elasto-plastic large deflection of the elements, including at post-ultimate strength state. 2) A simple and accurate deformation function for each type of the elements is selected. 3) Appropriate locations and number of checking points for plasticity are proposed. To take account of intermediate state between initial plasticity and full plasticity, an appropriate size of plastic zone at each checking point is assumed. This method is applied to several examples, and its usefulness and validity is demonstrated by comparing with the results of the finite element analysis. Necessary computer time for the example analysis by this new method was found to be 1/601/100 by F. E. M.