Abstract: The mechanical properties of unsaturated soils were a function of the degree of saturation or matric suction,and could be obtained based on currently available procedures.However,each procedure had its limitations and consequently cares should be taken in the selection of a proper procedure.Fractal approach seemed to be a potentially useful tool to describe hierarchical systems and was suitable to model the structure and hydraulic properties of unsaturated soils.The soil-water characteristics,unsaturated hydraulic conductivity function and unsaturated shear strength were derived from the fractal model for the pore-size distribution,and were expressed by only two independently physical parameters,the fractal dimension and air-entry value.The predictions of the proposed soil-water characteristics,unsaturated hydraulic conductivity and unsaturated shear strength were in good accordance with the published experimental data.