This paper describes the effect of geometric non-linearity on the deformation analysis for linear elastic grounds using the FE analysis. This FE analysis has been formulated by the finite deformation theory based on the up-dated Lagrangian scheme. A deformation characteristic is discussed in comparison the finite deformation theory and the infinitesimal deformation theory to study the effect of geometric nonlinearity. As a result, three main conclusions have been obtained. 1) At the time of small deformation, the both analyses lead the same results, 2) At the time of large deformation, because of the effect of surface expansions, the infinitesimal deformation analysis overestimates lateral displacements when compared with the finite deformation one, and 3) At the time of large deformation, because of the rotation effect, the finite deformation analysis overestimates vertical displacements on a place where the load concentrates when compared with the infinitesimal deformation one. To this end, careful choices are required to use deformation theory in treating a large deformation problem.