A red strontium aluminate phosphor (Sr_3Al_2O_6:Eu^(3+), Eu^(2+)) is synthesized using a solid state reaction method in air and reducing atmosphere. The investigation of firing temperature indicates that a single phase of Sr_3Al_2O_6 is formed when the firing temperature is higher than 1300℃. The effect of firing temperature and doping concentration on luminescent properties are investigated. Sr_3Al_2O_6 phosphor exhibits the typical red luminescent properties of Eu^(3+) and Eu^(2+).