Abstract: Based on the finite element method, a numerical investigation into the bonded repair efficiency of cracked plates under biaxial loading is presented. The main considerations are: reduction in the Stress Intensity Factor (SIF) at the crack tip, the maximum tensile stress in the composite patch and the maximum shear stress in the adhesive bond between patch and plate. Without the patch, a tensile or compressive stress parallel to the crack would have no effect on the SIF at the crack tip. While with a composite patch, there exists coupling effect between the normal stress parallel to crack and the SIF, and the coupling effect is significantly dependent on ply orientation of the patch.