Abstract: The spatial variability of the hydraulic conductivity in porous media is the base of the groundwater flow and trans-port. To aim at the limitation of the assumption of the isotropy of the hydraulic conductivity got from the geotechnical tests,the measured data in the Borden test are analyzed to illustrate the applicability and the illogicality of the assumption through reduction to absurdity.The effect of the anisotropy on spatial variability of the hydraulic conductivity is also summarized and the principle to determine whether the hydraulic conductivity field is stationary at different field scales is provided in this paper. Finally,some advices on the research of the spatial variability of the hydraulic conductivity are presented.