Areas where there is a bond imperfection or absence of a bond between the surface layer in the composite material is defined as a delamination. Delamination can occur in simple material to complex materials such as wind turbines. Therefore, the authors review some of the effects of initial crack size, location and lay-up configurations on the response delamination of layer sub-sections, wind turbine spar cap on 25 m wind turbine. Sub-section wind turbine use material E-glass / Epoxy prepeg . The simulation was performed using ANSYS with cohesive zone. Delamination occurs between the layer and modeled with interface element. It was found initial crack with a = 400 mm has reaction force about 3757.473 N, and for the smaller a = 200 mm has bigger reaction force about 5194.675 N. Initial crack associated with the thickness (t) at 1/2 t have a better resistance against delamination, while at 3/5 t, peak reaction force decreases. And the fiber orientation with unsymetric configuration has a reaction force smaller than symetric material (unidirectional).