The effects of Cu substitution for Mg on the properties of a MgZn ferrite sintered at low temperature were investigated. The sintering density of MgCuZn ferrite is variable with Cu content in the composition (Mg0.5-xCuxZn0.5O)Fe2O3. A good density, of about 4.5 g/cm(3), was obtained for x = 0.3 at a low firing temperature of 1050 degrees C. High electrical resistivities were obtained for x = 0-0.3. The dispersion permeability is observed above x = 0.3.