A novel red-emitting phosphor of Eu 3+ -activated molybdate was prepared at 850°C by a modified solid-state reaction. Photoluminescence (PL) results showed that the phosphor can be efficiently excited by UV–visible light from 350 to 550nm, and exhibited bright red emission at 614nm. XPS are taken to investigate the structure and compositions of this material. The crystallization and particle sizes of the phosphor have been investigated by using powder X-ray diffraction (XRD) and transmission electron microscopy (TEM). TEM images show that the grain size of the phosphor is about 30nm which is in full agreement with the theoretical calculation data from the XRD patterns.