Abstract <p>The electrical properties of a material representing a composite of epoxy resin, magnetic fluid, and carbon nanotubes are investigated. It is shown that in composites dried in the presence of a&#xa0;magnetic field, elongated conductive structures consisting of carbon nanotubes and magnetic fluid are formed. Their presence causes the appearance of anisotropy of the electrical properties of such composites. The anisotropy of the properties is studied by microwave waveguide methods, according to the frequency dependence of the reflection coefficient of microwave radiation from a periodic structure in which the composite under study was used as a damaged layer. It has been found that the electrical properties of the composite depend on the magnitude and direction of the magnetic field induction, as well as on changes in the concentration of components in the composite. Numerical modeling was performed and the importance of taking into account the anisotropy of the electrical properties of the formed structures when calculating the integral parameters of the composite is shown.</p>