We report on the annealing process dependence of the visible photoluminescence (PL) properties of the Pr3+-doped Ga2S3-GeS2-La2S3 glass, where emission intensities per ion depend not only on the Pr3+ concentration but on the annealing process after glass formation. It is demonstrated that enhancement of the photoluminescence to more than four times the intensity can be achieved through improvement on a procedure in the process. Multiple peaks were observed in the PL, and not only the total intensity but also the relative intensity of each peak was changed. Degree of the intensity enhancement was proved to depend on the excited states. (C) 2007 Elsevier Ltd. All rights reserved.