Abstract: This paper is concerned with the description of undrained response of saturated soils involving localized deformation. The average macroscopic response is estimated based on a homogenization procedure similar to that proposed earlier in reference . The formulation presented here is different from the original one, which is primarily due to a choice of the referential coordinate system. First, the case of drained response is addressed. Subsequently, the formulation relevant to saturated soils is outlined, in which both constituents (i.e. the intact and the shear band material) are assumed to respond in an undrained manner. A numerical example pertaining to undrained response of a dense sand specimen tested under plane strain conditions is provided, illustrating the influence of localization of deformation on the mechanical characteristics. The results of numerical simulations are fairly consistent with the experimental data.