Abstract: Investigates the modeling methods for three dimensional surface crack problems. Based on finite element method, 1/4-point displacement method and J-integral method are used to calculate the stress intensity factors along the entire crack front. Several meshing cases are studied. It is shown that, when using 1/4-point displacement method, the stress intensity factor results are sensitive to the crack front region size and non-sensitive to the mesh size. For J-integral method, the results are non-sensitive to both the mesh size and mesh style, and suitable to calculate the stress intensity factor of complex structures.