SmCo5 nanoparticles are one of the most important binary transition metal-rare earth systems for magnetic materials. SmCo5 nanoparticles were fabricated by a four-stage route. At first, pH value of mixed aqueous soluble with SmCl3 and CoCl2 was adjusted using NaOH. Secondly, two soluble metal-salts were forced hydrolysis to oxides under atmospheric refluxing at 80 °C. Then, oxide nanoparticles with a ca average size of 20 nm were prepared at 150 °C for 9 h through a convenient hydrothermal process. Finally, the SmCo5 nanoparticles were attained via hydrothermally prepared nanoparticles deoxidized using Na under the hydrogen stream at 400 °C. The SmCo5 nanoparticles are superparamagnetic at 300 K while the particles are ferromagnetic with Hc of 4.16×104 A/m at 5 K