In this study, Gd 3þ and Bi 3þ ions act to redshift the emission band to orange region, and to enhance significantly the maximum emission of YAG: Ce 3þ . On account that size mismatch between the host and the doped Gd 3þ ion, the crystal structure turns soft, and the emission spectra are not tuned from 540 to 570 nm but decreased the emission intensity. Accordingly, an effective way to increase emission intensity is to introduce Bi 3þ ion into the YAG: Ce 3þ , Gd 3þ phosphors. Experimental results show partial overlapping between the emission band of Bi 3þ ion and the excitation band of Ce 3þ ion, indicating that the energy transfer from Bi 3þ to Ce 3þ ions exists in the (Y 1:94 Ce 0:06 Gd)Al 5 O 12 : Bi 3þ phosphor. Bi 3þ ion can serve as the activator to provide energy for Ce 3þ ion via cross relaxation phenomenon. Therefore, the (Y 1:94 Ce 0:06 Gd)Al 5 O 12 : Bi 3þ phosphor could have potential applications in warm white LEDs.