This work reports on the study of the microstructure and electrical properties (conduction and superconduction) of YBa2Cu3O7-x (Y) and polypropylene (PP) composites. For the purpose of enhancing and improving their conductive properties, different amounts of carbon black (N) a nd copper (Cu) were incorporated into these composites, and the effects of N, Cu and Y were determined, both on the microstructure of PP and on the electrical properties of the resulting composites. The complex systems on the basis of PP/Cu/Y and PP/N/Y were sintered in order to study their mechanical characteristics, their morphology and the superconductor properties of the end products.