Abstract: In this paper,the fractal theory is used to evaluate the fracture network complexity of Nanwu section in Tangshan mine.The higher of the calculated fractal dimension means the more complexity of the mine structure,which will increase the influence of mine safety production.The result shows that the fracture tracing line is scattered from a centralized distribution degree from the fifth coal seam to the ninth coal seam.The complex structure areas are mainly located in the direction of North and South by East,but the East by middle direction and Southwest corner of Nanwu section have relative simple and stable structure.