||Methodology for analysis of wave drift forces acting on various type floating structures has been developed actively, by now. However, these method was focused on rigid structures mainly. Recently, very large floating structures, such as floating airport, floating bridge, MOB, and so on. are being designed and developed actively. The particular feature of these type structure is deformability in analysis of nonlinear hydrodynamic forces, deformability causes complexity. In this paper, the formula of End-order wave forces is derived rigorously in the view point of near field approach. Some examples of application are given in this paper This formular can be used for multi-body system. for which far field method may not be applied.