An efficient solvothermal method was developed to prepare CeO 2 microcrystals with different shapes using a polyol–ethanol mixed solvent as the reaction medium. The as-synthesized product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and UV–vis diffuse reflectance spectroscopy (DRS). It was found that different kinds or amounts of polyols and the concentration of oleic acid have significant impacts on the well-defined CeO 2 microcrystals. The as-synthesized CeO 2 microcrystals displayed different optical absorption properties and different photocatalytic performances for the degradation of Rhodamine B (RhB) under UV and visible light irradiation, which was used to model sunlight.