Abstract: Nowadays, green synthesis of nanoparticles has great interest and achievement due to its eco-benign and low time consuming properties. In this work, Ceria nanoparticles is Synthesized using Ricinus communis (Castor oil) leaf extract. The Synthesized nanoparticles are characterized by UV-Vis spectroscopy, dispersive X- ray analysis (EDAX), which is attachment of scanning electron microscope (SEM). Crystalline nature and purity are revealed by X-ray diffraction (XRD) and their FTIR spectra are examined to identify the effective functional groups present in the synthesized nanoparticles. Raman studies show a characteristic peak at 461 cm−