Soil saturation degree plays an important role in mechanic behavior of soil-concrete interface. Laboratory experiments are conducted on soil-concrete interfaces by using improved simple shear apparatus, where three soil saturation degrees and five normal stresses are taken into accounted, respectively. The experiment data show that failure of the interface still satisfies the Mohr-Coulomb criterion under fixed soil saturation degree. With higher soil saturation degree, both shear strength and friction angle of the interface decrease monotonously, but cohesion force of the interface first increases and then decreases after reaching a peak value. When soil saturation degree increases, failure position of the interface moves from concrete surface to soil inner part.