Abstract: Based on the Biot’s theory,the velocity equations were derived in a half-space of partially saturated soil with pervious and impervious surfaces.The effects of the saturation on velocity,displacement,energy-flux distribution and trajectory of Rayleigh wave were analyzed by numerical methods.It was shown that the saturation effect on the velocity of Rayleigh waves was not very obvious,but there was a substantial influence of saturation on the displacement,trajectory and energy-flux distribution of Rayleigh waves.Even a slight decrease of full saturation might lead to an obvious decrease of the displacement and the size and shape change of the trajectory.The compressional wave components of Rayleigh wave energy would slightly increase with the decreasing saturation.The propagation depth of Rayleigh waves was about 2.0 times of wavelengths.