The inclined surface cracks are under the mixed mode I，II，III loading conditions. In order to study the surface crack growth the stress intensity factors of the front of half-circular surface crack are calculated according to fracture analysis code-3D(FRANC3D). And the influences of inclination angle of the surface crack and the orientation angle on I，II，III mode stress intensity factors were analyzed. I mode stress intensity factor increases along the crack front with increasing inclination angle. And I mode stress intensity factor of the same inclination angle is symmetrical with respect to the orientation angle of 90 degree. II，III mode stress intensity factors are the maximum when the inclination angle is equal to 45 degree. And the behavior of II，III mode stress intensity factors along crack front for the inclination angle of 15 and 30 degree is identical with that of inclination angle of 75 and 60 degree, respectively.