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The effect of a uniform external magnetic field on the effective permittivity of magnetorheological elastomers (MREs) was simulated. It is considered that capacitance of plane capacitor filled with MRE and, thus, the effective permittivity of MRE is dependent on the external magnetic field. This effect is called magnetodielectric effect or magnetocapacitance effect in MRE. The model was developed to qualitative explain the experimental results obtained earlier. The model was developed to analyze behavior of spherical equally sized magnetic particles uniformly distributed in elastic matrix under the external magnetic field. The change of capacitance of capacitor filled with MRE was calculated. We considered dipole-dipole interaction between particles. Particles were assumed as soft magnetic, so we put interaction of particles magnetic moments with external magnetic filed only as orienting. We took Hooke’s law, as particle-matrix interaction – each particle is connected with its initial position by ideal string. The particles were shown to tend to the formation of chain-like structures when magnetic field is applied, and the displacement of particles and, therefore, the value of magnetodielectric effect, was shown to be dependent on the elastic properties of matrix and intensity of magnetic field. Dependence on particles volume concentration was also simulated. The observed field-induced phenomena evidence the attractiveness of MREs as novel promising materials in family of composite multiferroic materials.