Nano ferrites, particularly spinel ferrites, have attracted more attention in recent years due to their technological applications. By incorporating suitable divalent, trivalent or tetravalent impurities into the spinel lattice, the properties of nano ferrites could be tailored. Particle size plays a key role in the magnetic behaviour of materials as well as in biomedical applications. They can be used in biomedical applications by manipulating particle size, shape and magnetic behaviour. Sol gel method was primarily used in the preparation of Cu1-xNixFe2O4 (x= 0, 0.5, 1) nanoparticles in this study among the synthesis methods. In the synthesis process, iron nitrate and nickel, copper ferrite were used as oxidizers and green reducing agent was used as fuel. For the synthesisof Cu1-xNixFe2O4 (x= 0, 0.5, 1) green reducing agents such as honey, aloe veraextract, egg white, lemon juice and sugarcane juice were used and the resulting property changes were analyzed. In CuFe2O4 nanoparticles, nickel (Ni2+) ions are substituted by Fe3+ ions. Particle size, surface morphology and magnetic behaviourwere studied in CuFe2O4 nanoparticles by substituting the Ni2+ ions instead of Fe3+ ions