In this study, a usefulness of the iterative solution procedures is reviewed for the elasto-plastic large deflection analysis of imperfect plates by finite element method. Three typical solution techniques such as simple incremental(SI) method, Newton-Raphson(NR) method and modified Newton-Raphson (mNR) method are compared. It is concluded that for thin plates which are given rise to the large deflection, iteration for the convergence of the unbalance force should be performed and in this case mNR method is more useful than NR method since the computing time of the former becomes to be a half of the latter, in which the accuracy of the result remains same. For thick plates or thin plates with large initial deflection, however, the use of SI method is quite better since the unbalance force may be negligible.