Finite element analyses based on infinitesimal deformation and finite deformation theories are carried out to investigate the mechanism of the localized deformation of normally and over consolidated clays in drained shear tests. For this purpose, an isotropic hardening elastoplastic model for soils, named subloading tij-model, is used in the analysis. Two different geometrical conditions are assumed. – plane strain condition (2D) and triaxial condition (3D). The developments of shear bands in clays in these conditions are well simulated by the present finite element analyses.