A　novel　nano　red-emitting　phosphors　Ca0.5Sr0.5MoO4:Eu3+　were　successfully　synthesized　via　the　sol-gel　method　using　citric　acid　as　a　chelate.　The　resultant　powders　were　characterized　by　X-ray　diffraction,　scanning　electron　microscopy,　and　photoluminescent　spectroscopy.　The　results　show　that　the　particle　size　of　the　synthesized　phosphors　is　about　700　nm.　It　also　shows　that　the　synthesized　phosphor　powders　can　be　effectively　excited　at　the　wavelengths　of　395　nm　in　ultraviolet　light　area　and　467　nm　in　blue　light　area,　and　it　has　an　intense　red　emission　at　615　nm.　Furthermore,　the　optimal　concentration　of　Eu3+　in　Ca0.5Sr0.5MoO4:Eu3+　is　about　10%,　the　best　firing　temperature　is　at　1000°C　and　the　emission　intensity　becomes　five　times　stronger　as　the　introduction　of　Na+　acting　as　charge　compensation　in　Ca0.5Sr0.48MoO4:0.01Eu3+,　0.01Na+.　It　is　considered　to　be　an　efficient　red-emitting　phosphor　for　white　light-emitting　diodes　(w-LEDs).