Submicrometer-sized hollow Eu 2 O 3 spheres with a shell thickness of about 75 nm and inner diameter about 690 nm have been synthesized through a sol–gel method using PS/PE microspheres as templates. X-ray powder diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FESEM), and photoluminescence (PL) spectroscopy have been used for the characterization of the obtained hollow Eu 2 O 3 spheres. The PL peak is obviously broadened compared with that of bulk Eu 2 O 3 . The mechanism of the formation of the hollow Eu 2 O 3 spheres was discussed.