Core-shell magnetic nanoparticles have received significant attention recently and are actively investigated owing to their large potential for a variety of applications. In this study, the synthesis and characterization properties of magnetite @ polyrhodanine (Fe 3 O 4 @ PRh) core-shell nanoparticles have been investigated. To monitor the morphology, size, structure, thermal stability, and magnetic properties of nanoparticles, scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetic analysis, and vibrating sample magnetometer were carried out. The results indicate that a thin film of polyrhodanine was coated on the surface of Fe 3 O 4 nanoparticles. The coated shell of polyrhodanine can protect the Fe 3 O 4 cores from being oxidized. Also, the results presented the crystalline, small size, and high magnetization value for the core-shell structure. C