Abstract: Field and laboratory obervations showed that en echelon fractures within fracture zones havea Riedel within Riedel structure. The tensile failure mechanism of formation of en echelon fractures can be described by the pile-upe of shear crack-dislocations . A fractal model can be used to simulate the Riedel Within Riedel geometry , allowing the direct measurement of the fractal dimensions of en echelonfracture systems. The energy dissipation of the en echelon fracture system can be deduced by using afractal damage evolution model which explains the evolution process of en echelon fracture systems.The fractal nature of the fractures can be used to derive an accurate estimation of total energy dissipa-tion.