In this paper, an extended finite element method (XFEM) is employed to simulate a plate with through thickness cracks. The numerical formulation is done using Mindlin-Reissner plate theory. A crack in the plate is modelled by using Heaviside and crack tip enrichment functions. The stress intensity factor is computed using domain form of an interaction integral. Different problems of through-the-thickness cracks are simulated and compared with available literature results. Several problems of plate with crack under different boundary and loading conditions are solved by XFEM. Keywords: XFEM, Crack, Plate bending, Mindlin-Reissner, Stress Intensity Factor.