We improved a magnetic composite model that combines the Jiles−Atherton model and Eshelby’s equivalent inclusion method to consider misoriented martensite particles. The magnetic permeability of type 304 stainless steel were analyzed by using both experimental data on the orientation distribution of type 304 stainless steel specimens and the improved model. We found that the model is able to qualitatively explain the variation of permeability with the orientation angle and orientation distribution, an effect that depends on the direction of the excitation magnetic field.