Cerium oxide (ceria) nanoparticles were synthesized using cerium nitrate and ammonium carbonate as precursors. As-synthesized CeO2 powders were calcined between 400-850°C for 2 h. The samples were characterized by thermogravimetric analysis, X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared, UV-Visible, photoluminescence and Raman spectroscopies. The FTIR spectrum exhibits strong broad band below 600 cm-1 which is due to Ce-O stretching mode to confirm the formation of pure CeO2. It is shown that average particle size increases as calcination temperature is increased and the absorption is red shifted. PL studies observed that emission band is blue shifted and intensity of emission peaks decreases with increase in calcination temperature. Raman spectrum is characterized by the presence of a very strong band near 464 cm-1. The desired structural and optical properties of CeO2 nanoparticles make it as a promising material for photocatalytic and optoelectronic applications