Abstract: The influences of density on the stress-strain properties and strength of sand with the same gradation are investigated by using the triaxial consolidation drained shear tests on the samples with different densities. The experimental results show that the density has little impact on the shape of stress-strain curve. The axial strain at failure as well as the axial and volumetric strains for deformation is significantly affected by the density. Through analyzing the influences of density and confining pressure on the axial and volumetric strains for deformation, the relationships among strains, densities and confining pressures are established. The density has great influences on the deviator stress ratio at failure, while the influences on the residual deviator stress can be ignored. The strength index increases with the increase of the relative density generally. In terms of the nonlinear indexes such as φ₀ and Δφ, its relationship with change of the relative density is approximately linear, and the internal friction angle increases by 0.66 degrees with the increment of D_r of 0.1.