A series of erbium-doped fluoro-bromozirconate glasses modified by various concentrations of Br- was prepared using the melt-quenching method. The mid-infrared fluorescence intensity (2.7μm) was improved by increasing the content of Br-. The differential scanning calorimetry, x-ray diffraction, Fourier-transform infrared spectra, Raman spectra, and mid-infrared luminescence spectra were measured. The decreased phonon density shows that the structural changes due to inserting Br- can enhance the mid-infrared luminescent intensity. From the Judd-Ofelt analysis, it was found that the intensity of Ω2 was enhanced with the introduction of Br- and shows greater asymmetry and stronger covalency. Using the Fuchtbauer-Ladenburg theory and McCumber theory, the emission cross section (2.9×10-20 cm2) and absorption cross section (1.68×10-20 cm2) at 2.7μm were determined. Hence, erbium-doped fluoro-bromozirconate glass is a potential material for application in the mid-infrared region.