Abstract: The synthetic fracture criteria is based on the normal-stress,shearing-stress and the impact of plastic area.The new fracture criteria is proposed here to replace the one where only the singular term is considered.The conditions of application of the synthetic fracture criteria to the mixed mode crack problems have been given by the analysis and comparison between the theoretical solutions and experiment results.The result that is used in conjunction with the synthetic fracture criteria for problem of I-I mixed mode state is satisfying.