Abstract: Based on the one-dimensional dislocation crack model and the energy calculations, a two-dementional dislocation crack model is presented,which is an elliptical crack caused by the dislocation pile-up groups.The total potential energy of this model is obtained. Following the principle of conservation of energy, the equilibrium length of the crack and the critical stresses for growing cracks are given. All results are compared with Griffith's solutions for Mode-I through crack and the elliptical embedded crac...