The deformation and strength characteristic of rockfill is different when it is dry or wet. The wetting effects should be a major factor in the long-term settlement of a rockfill dam. The 160 m high Yellow River Xiaolangdi dam is a rockfill dam with inclined core clay. Moistening laboratory tests were carried out to investigate the deformation and strength characteristic of the rockfill in the Xiaolangdi dam. Based on the test results, two-dimensional consolidation numerical simulations on the dam employed nonlinear stress strain constitutive model were conducted to investigate the effects of wetting on the deformation performance of the dam.