Ferrite is a class of magnetic material. Naturally occurring ferrite is the ferrous ferrite (Fe3O4) as "Load Stone". In early days it was considered as ferromagnetic material. But latter on L Neel realized that, material consists uncompensated anti parallel spin arrangement and hence named as "Ferrimagnetic material. Ferrite is a special class of Ferrimagnetic material having interesting intrinsic properties. Basically Farous ferrite Fe3o4 is having double oxides FeO & Fe2O4. The properties can be altered by substituting divalent iron ion by divalent cations from transition elements. Properties can be significantly modified by substituting trivalent iron ion by another trivalent cations. Ferrites are found to be technologically and commercially useful magnetic material. Due to highly electrically resistive and low magnetic behavior as well as negative temperature coefficient of resistance along with low magnetic loss ferrites can be used at high frequencies. They find applications in the fields like elecommunications, electronic industries, data storage & processing. Aluminum substituted Copper CuxAl2yFe2-2y ferrites are prepared to study structur, electrical & magnetic properties.