A series of luminescent Ba_0.79Al_10.9O_17.14:xEu (x = 0.005-0.12) phosphors were prepared by high-temperature solid-state reaction in air atmosphere. The coexistence of Eu²⁺ and Eu³⁺ was observed and verified by photoluminescence (PL) and photoluminescence excitation (PLE) spectra, X-ray photoelectron spectra (XPS), and diffuse reflection spectra. The band emission peaking at 430 nm was assigned to 4F⁶5D-4F⁷ transition of Eu²⁺, and another four emissions peaking at 589, 619, 655, and 704 nm were attributed to 4F-4F transitions of ⁵D₀-⁷F_J (J = 1, 2, 3, 4) of Eu³⁺. The related mechanism of self-reduction was discussed in detail. The color of the Ba_0.79Al_10.9O_17.14:xEu phosphors could be shifted from blue (0.23, 0.10) to red (0.42, 0.27) by doping Li⁺ ions, and the temperature dependence properties were investigated.