The rare-earth-free Mn4+-activated oxide red phosphors draw great attention for their potential applications in the field of light-emitting diodes (LEDs). In this work, the red-emitting Mn4+/Zn2+:Y3Al5O12 phosphor, showing strong red emission peaked at similar to 672 nm as a result of the spin-forbidden (2)E(2)g -> (4)A(2g) electron transition of Mn4+ ions under 478 nm excitation, was synthesized by a traditional solid-state reaction route in air. The microstructure and luminescent performance of this red-emission phosphor was investigated in detail. From the experimentally measured spectroscopic data, the crystal field strength (Dq) and the Racah parameters B and C were calculated, respectively. In addition, Zn2+ dopant was found to be beneficial for enhancing Mn4+ luminescence. Subsequently, Mn4+/Zn2+:YAG glass ceramic was successfully prepared via using mn(4+)/Zn2+:YAG phosphors incorporated into tellurate glass. A tunable lighting device was successfully achieved by coupling the red-emitting Mn4+/zn(2+):YAG GC with the commercial blue chips and Ce3+:Lu3Al5O12 GC.