Abstract: Based on the Monte Carlo method, an improved random fracture network generation algorithm is proposed by introducing the correlation function of the length and aperture of fractures. The corresponding program is developed on the platform of MATLAB. The generated two-dimensional fracture network is compared with the real fracture field generated by Boolean simulation. From the comparison, the validity of the improved algorithm and the program is verified. Then seepage analysis of the fractured network was carried out based on the discrete fracture network model considering the correlation between the trace length and apertures. The distribution of fracture flow at the downstream boundary and the distribution of water pressure inside the fracture network are analyzed in this study. Analysis results show that the consideration of correlation between the trace length and apertures can better reflect the structural characteristics of fracture network seepage, which demonstrates the rationality of the proposed method. The development of random fracture network model can provide a sound theoretical basis for seepage control problems often encountered in the hydropower engineering.