Novel greenish-yellow light long-lasting afterglow material, Eu2+-doped CaO-CaBr2-SiO2 phosphor system, is prepared by the conventional high-temperature solid-state method. Photoluminescence (PL) spectrum reveals that it exhibits a strong blue emission band centered at 469nm with some asymmetry on the long wavelength side, while this phosphor emits greenish-yellow light and shows strong long-lasting phosphorescence after it is excited with 365-nm UV light. The phosphorescence lasts for more than 1 h in the light perception of the dark-adapted human eye (0.32 mcd/m(2)). The possible phosphorescence mechanism is also investigated.