In this thesis, chitosan core-shell magnetic nanoparticles were prepared and functionalized with methyl histinate ligand and cobalt nanoparticles immobilized on the surface of these particles. The MNPs-Cs @Co-His Catalyst was characterized by ICP, XRD, SEM-EDX, VSM, FT-IR, Fe-SEM and TEM analyses. Catalyst magnetic properties, by VSM techniques, was confirmed. Presence of cobalt was evaluated by ICP and SEM-EDX techniques. XRD technique was used to prove the magnetic phase and presence of Co. TEM technique was used to demonstrate the nanoscale catalyst. Performance of MNPs-Cs @Co-His catalyst in the C-C Suzuki and Heck coupling reactions was studied, and great results were obtained. In this project, the heck reaction was carried out by the cobalt catalyst, in mild and green conditions (low temperature and green solvent).Moreover, the presence of this metal and these optimum conditions are the advantages of this catalyst over previous catalysts. An evaluation of the efficiency of this catalyst in Suzuki reaction demonstrated results, and utilizing the free-palladium catalyst, such as cobalt, is the most notably point of Suzuki reaction. At the end of each reaction the prepared catalyst was extracted and reused simply by using the external magnetic field.