A red phosphor of Eu3+, Bi3+ co-doped Sr(3)Ga(2)O5Cl(2) is synthesized by solid-state reaction for the first time. The XRD Rietveld refinement presents that the compound crystallizes in a monoclinic crystal system with space group C-2(2) - P2(1). Under the excitation of 393 am, Sr3Ga2O5Cl2:Eu3+ shows an efficient red emission with the dominated peak at 618 nm (D-5(0)-F-7(2)). With the introduction of Bi3+, the emission intensity of Eu3+ rapidly increases due to the energy transfer from Bi3" to Eu3+. The dominated emission peak shifts from 618 to 703 nm (5D0-7F4), implying that the crystal environment of Eu3+ in Sr3Ga2O5Cl2 possibly becomes serious distortion. With the increase of temperature from 20 to 250 degrees C, the Eu3+ single doped Sr3Ga2O5Cl2 reveals an excellent thermal property, but the thermal stability of Eu3+, Bi3+ co-doped Sr3Ga2O5Cl2 appears severe degradation, which indicate that a complicated energy transfer process possibly occurs between Eu3+ and Bi3+. Based on the configurational coordinate diagram, the phenomenon can be reasonably explained. (C) 2015 Elsevier Ltd. All rights reserved.