The nanoparticles of cerium oxide were synthesized using the novel photolysis method. The nanoparticles characterized by X-ray diffraction (XRD), UV-Visible spectroscope (UV-Vis), transmission electron microscope (TEM), scanning electron microscope (SEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Photoluminescence spectrum (PL). The size and structure of nanoparticles were obtained from (XRD) and found to be 13nm and cubic structure. The results from (TEM) and (SEM) showed agglomeration of particles and it in nano size. Strong peak at 296nm appeared when using UV-Vis while six emission peaks showed from PL spectrum. The dielectric properties of nanoparticles were studied for different frequency and showed a decrease it with increased frequency.