Sm - Co - Fe - Cu - Zr sintered high-temperature permanent magnets (HTPM) produced by the «POZ-Progress» Company are studied. The microstructure of the magnets is determined by scanning electron microscopy and x-ray diffraction analysis. The Curie temperature and the magnetic properties of the materials are described. The hysteresis loops of the magnets are measured in strong pulsed fields at room and elevated temperatures. The temperature dependence of the magnetic susceptibility is plotted using the method of compensated transformer in a variable magnetic field