Abstract: Experimental research on 8 concrete beams with high strength stirrups under concentrated load has been performed. Based on the surface-crack distribution of shear members, fractal geometry theory is employed to investigate the cracking and failure process of concrete beams. The result shows that the fractal dimensions on the surface of concrete beams can be used to describe the state of cracking damage under the influence of various stresses. For the fractal dimension of the crack distribution, the damage evolution is a process of dimension increase. Moreover, a relationship has been established between the fractal dimension and the damage variable. Therefore, the fractal dimension can be used to describe the characteristics of crack and the damage degree of concrete beams.