Eu2+-doped NaMgPO4 phosphor was prepared by conventional high-temperature solid-state reaction. The photoluminescence excitation and emission spectra were investigated. The phosphor can be excited by UV-visible light from 220 to 430 nm to realize emission from 4f(6)5d(1) -> 4f(7)(S-8(7/2)) transition in the blue range. The 4f(7)(P-6(7/2)) -> 4f(7)(S-8(7/2)) transition in the 4f(7) electronic conguration of Eu2+ at 360 nm was observed at low temperature. The luminescence absolute quantum efficiency, the crystallographic sites and the microstructure of Eu2+ ions doped in NaMgPO4 lattices were reported. The multiple sites structure of Eu2+ ions in NaMgPO4 lattices was discussed. The luminescence quenching temperatures and the thermal activation energy for NaMgPO4:Eu2+ were obtained from the temperature dependent (18-300 K) luminescence decay curves. Eu2+ ions have the "disordered environment" in NaMgPO4 lattices. The relation between the luminescence thermal stabilities and the crystal structures were discussed. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.013202jes] All rights reserved.