Abstract: Under rainfall condition，the existence of fractures provides advantage for rainfall infiltration which may lead to the uneven distribution of rainwater，and the fractures are preferentially saturated，thus a head difference forms between the fracture network and the matrix and，furthermore，a water flow exchange occurs． In this paper， by representing the fractured soil as a dual-porosity system consisting of fractured network and matrix，the pressure head distribution of the matrix and the fracture network are obtained based on the Richard seepage equation of double-pore model and the Galerkin method，and the results are compared with those of Hydrus-1D，with the rationality of the method being verified． It is shown that ( 1) the wet peak surface distribution of the matrix is different from that of the fracture network，the former is steep while the latter is gentle; ( 2) the wider the matrix，the greater the effect of rainwater infiltration on the slope stability; and ( 3) when the matrix width becomes smaller， the rainwater infiltration is more and more uniform，and the depth of slope stability affected by rainwater infiltration becomes smaller，while the increase in saturation makes the shear strength of shallow soils decrease more． 

Key words: fractured soil, dual-porosity system, Galerkin method, wet peak surface, slope stability