Abstract: The traditional subgroup parameters are generated under the assumption that only one resonant nuclide is in the system. However, this assumption is not in accordance with the real condition of fuel pellet which may contain different kinds of nuclides, and the resonance interference effect can’t be consi-dered in this method. To solve this problem, a new calculation method of subgroup parameters was proposed in this paper. The effective cross sections of all resonant nuclides in the fuel were used to make the resonance integral table, and the resonance interference effect was treated during this procedure. The numerical results show that the new subgroup parameters have better accuracy for resonance interference treatment.