Abstract: The bearing capacity of rock-socketed long-piles depends on the shear strength of pile-rock contact surface. Based on the research method of rock mass structural surface intensity and introducing the shear strength formula of two-phase contact medium rough surface described by fractal dimension, the shaft resistance transfer model of a rock-socketed pile expressed by fractal dimension is set up. Then the analytical solutions of the pile shaft resistance and pile axial force under the elastic condition are obtained. Based on the solution obtained, the influence law that how the fractal dimension influence the shaft resistance, pile axial force and the load distribution ratio of pile tip were discussed. The research show that in a certain range and under the same conditions, the higher the fractal dimension of rough D is, the higher the concentration extent of shaft resistance in the upper part of a pile is，the smaller the depth of a load transfer and the load distribution ratio of pile tip are. The smaller the length-diameter ratio l/d is, the bigger the load distribution ratio of pile tip is. Comparative analysis result of an engineering example shows that the calculated values by the present method agree well with the measured data.