The boundaries of glassformation fields were determined in the La₂S₃–Ga₂S₃–Nd₂S₃ system by the methods of physico-chemical analysis. Thermal decomposition of obtained glasses and IR-spectra were studied. It was determined that these glasses are stable in air at 880 K. The bands characterizing Me–S bond in IR-spectra of glasses are of more intensity and shifted to the high frequency domain compared to those in the spectra of initial crystalline components what is, probably, conditioned by enhancing covalency of Me–S bond.