hermodynamic properties including characteristic temperatures and thermal parameters of rare-earth (RE) ions doped lithium-yttrium-aluminium-silicate (LYAS) glasses have been investigated. Glass transition temperature (Tg), onset crystallization temperature (Tx), crystallization temperature (Tc), temperature difference value (DT) and Saad-Poulain criterion (S) in Tm3+/Yb3+ co-doped LYAS glasses are obtained to be 814, 1008, 1043, 194 and 8.34 °C, respectively, and the corresponding values of Sm3+ doped LYAS glasses are derived to be 825, 1002, 1053, 177 and 10.94 °C. Evaluations on thermodynamic properties indicate that LYAS glasses are a promising candidate for drawing optical fibers in the temperature range of 850−950 °C.