Abstract: Based on the capillary effect of the sand, a test technology is suggested to prepare the dense sand sample with different sedimentary directions. A series of triaxial tests are performed to study the influence of the sedimentary direction on the strength and the volume change of the sand sample, meanwhile, a fitting formula is suggested for the relation between the ultimate strength and the sedimentary direction. Main study results show that the sedimentary direction has a great influence on the ultimate strength and the deformation characteristics of the sand for the direction in the range between 0°~90°, but it has little influence on the residual strength of the sand. When the sedimentary direction is close to the failure plane direction, which is suggested as 45°+ ϕ/2, the test sample is easier to reach the failure stage and the ultimate strength is low. The suggested fitting formula could reflect the relation between the sedimentary direction and the ultimate strength reasonably, in which the confined pressure has an influence on the relation. Meanwhile, the formula could be used to predict the most unfavorable sedimentary direction.