Abstract: Reduced graphene oxide supported Ni nano-particles magnetic composites were prepared by reduction of graphene oxide and nickel ions in water with hydrazine hydrate and the graphene oxide was synthesized by the Hummers method. The changes of the contents and microstructures of the graphite and the magnetic properties of the composites were observed by FTIR, XRD, SEM, Raman and VSM. The results showed that the graphene oxide contained a large amount of oxidizing groups, and their intergranular distances were larger than that of graphite and exhibited amorphous characteristics. The nickel nanoparticles were distributed on the surfaces and interlayers of graphene and were accompanied by segregation. The saturated magnetization of the composites increased from 0 to 50 emu/g and the coercivity increased from 25 Oe to 205 Oe when the addition of nickel changed from 10% to 50%.