Many constitutive models have been proposed in relation to the liquefaction analysis. The applicability of the models to dense sand, however, has not been well established. The applicability of the model for dense sands is important for evaluating the improved ground. The aim of the present paper is to study the applicability of an elasto-plastic model for sand to the dense sand. In the analysis, we have used an elasto-plastic model for sand proposed by the first author. The cyclic elasto-plastic model has been derived based on a non-linear kinematic hardening rule. The following three points are incorporated into the model: generalized flow rule, a cumulative, strain-dependent characteristic of the plastic shear modulus and a fading memory characteristic of the initial anisotropy. The model was verified its effectiveness for medium dense sands. In the present study, the applicability of the model to the dense sand has been studied based on the triaxial test results of dense Toyoura sand. It is found that the numerical results by the proposed model can well reproduce the liquefaction strength curve. The effective stress path as well as the stress-strain relation during cyclic loading are well reproduced by the proposed model.