Abstract: A number of large-scale triaxial tests are performed to investigate the wetting deformation behavior of a slate rockfill material. The relationship among wetting volumetric strain, shear strain, confining pressure and stress level is analyzed. The test results show that the wetting volumetric strain and the shear strain increase with the increase of both the confining pressure and the stress level. Using the test results, the applicability of Shen's wetting deformation model is verified for the test soil. It is found that Shen’s wetting deformation model can not satisfactorily reflect the wetting volumetric strain, but it can suitably reflect the relationship between the wetting shear strain and the stress state. By analyzing the shear strength behavior after wetting, the wetting under different stress levels has little influence on the strength parameter of the coarse-grained soil.