Abstract <p>This paper proposes a theoretical model for the magnetorheological properties of magnetic elastomers composed of micron-sized particles, which are magnetizable, have no intrinsic magnetic moment, and occur in a soft polymer medium. The study examines two types of composites: initially isotropic ones (synthesized in the absence of magnetic field) and anisotropic ones (polymerized in a magnetic field promoting aggregation of the particles into anisotropic structures). The data obtained show that the formation of anisotropic structures at the stage of the synthesis leads to a substantial increase in the macroscopic shear rigidity of the composite. The theoretical results are in quantitative agreement with experimental data.</p>