This study discusses the length effect of the downward inclined surface to apply the inclined interface surface design of the composite material under shear loading. The fracture parameter is analyzed by finite element method of the ANSYS. If the negative shear displacement is applied, energy release rate is reduced further to about the increasing inclined length, and the positive shear displacement applied, it had increased rather. If the negative shear displacement is applied, the reduction in the energy release rate in crack tip is found to be affected by the reduction in shear stress. If the positive shear displacement is applied, the increasing in the energy release rate in the crack tip is found to be affected by the increase in shear stress.