In order to develop a high gain medium for fiber lasers operating at 3-5 μm waveband0-0. 4%in weightPr3+ ions doped Ge12As20.8Ga4Se63.2 selenide chalcogenide glasses were prepared and the 0. 2%in weightPr3+ ions doped one was successfully drawn into step-index double-cladding fiber with the lowest loss of 2. 95 dB/m@6. 58 μm by a multistage rod-in-tube method. The electron-probe measure microanalysisEPMAX-ray diffraction XRDdifferential scanning calorimeterDSCfield emission transmission electron microscopeFE-TEMtrans mission and mid-infrared fluorescence spectra were carried out to analyze the dispersion of Pr3+ ions in glassthe im purity contentsthermal and optical changes caused by the Pr3+ ions’introduction. By analyzing the absorption and emission measurements of the serial glasses with the Judd-Ofelt theorythe Judd-Ofelt strength parameterstransi tion probabilitiesexited state lifetimebranching ratiosand emission cross-sections were also calculated. This sel enide chalcogenide glass has high Pr3+ ions’solubility and emission characteristicgood thermal stability and fiber forming performanceindicating that it has potential to be used as mid-infrared laser working medium. © 2022 Chines Academy of Sciences. All rights reserved.