Novel Ga-Sb-S chalcogenide glasses doped with different amount of Dy3+ ions were prepared. Their thermal stability, optical properties, and mid-infrared (MIR) emission properties were investigated. The glasses show good thermal stability, excellent infrared transparency, very low phonon energy (similar to 306 cm(-1)), and intense emissions centered at 2.95, 3.59, 4.17 and 4.40 mu m. Three Judd-Ofelt intensity parameters (Omega(2)= 8.51 x 10(-20) cm(2), Omega(4)=2.09 x 10(-20) cm(2), and Omega(6) = 1.60 x 10(-20) cm(2)) are obtained, and the related radiative transition properties are evaluated. The high quantum efficiencies and large stimulated emission cross sections of the MIR emissions (88.10% and 1.11 x 10(-20) cm(2) for 2.95 mu m emission, 75.90% and 0.38 x 10(-20) cm(2) for 4.40 mu m emission, respectively) in the Dy3+-doped Ga-Sb-S glasses make them promising gain materials for the MIR lasers. (C) 2015 Published by Elsevier Ltd.