Based on the capillary theory and Sierpinski space hypothesis

a fractal model for unsaturated seepage in fractured rock masses of function among capillary pressure

effective water saturation and relative permeability coefficient is established. In order to provide evidence to unsaturated seepage flow theory

the box dimension method is studied according to the technique of Monte-Carlo three-dimensional network simulation. The relationship between fractal dimension and unsaturated permeability is studied. A calculation example in Nuozhadu slope is given .The comparison results of proposed model and the Brook-Corey model indicate that the proposed model seems to be adequate to describe the fractured rocks for small ranges of fracture aperture and the relative permeability is mainly influenced by the maximum fracture aperture.