This paper uses the fractal theory of pore structures for porous media to study the fractal characterization of pore structure for nine numerical rocks. The results show that the fractal dimension of solid phase is usually greater than the pore fractal dimension, and its fractal scaling regions is less than the one of pore phase. This indicates that the numerical rock is an approximate two-phase fractal porous media. The porosities, volume fractions and permeabilities of nine numerical rocks are predicted. The results show that the fractal theory about pore structures of numerical rocks is effective in describing the porosity and permeability. Moreover, it seems to be more effective for solid phase in approximate two-phase fractal porous media. When predicting permeability using the fractal theory, it is very important to accurately determine the maximum pore size and the range of statistical self-similarity. By comparing the two kinds of predicted permeabilities，it is found that the FT method used by this paper is more accurate, more general and less computational cost than the PNEM method which has been worldwide used.