Germanium-based sulfide glasses in the Ge-Sb-S system have been elaborated and studied. A relationship between the structure, the composition and the linear optical properties of the glass has been established. The effects of the introduction of Sb on the structure using IR and Raman spectroscopies and on the linear refractive index have been discussed. We have shown that the progressive introduction of Sb2S3 in the glass system (1 - x)GeS2-xSb(2)S(3) (with x = 0.10, 0.20, 0.40, 0.62 and 0.80) decreases the number of GeS4 units in the glass network. As results, the glass transition temperature, the Vicker's microhardness and the stability of the glass against crystallization decrease dramatically. An increase in the density and the linear refractive index as well as shift of the absorption bandgap to infrared have also been observed. Similar behavior has been observed for the glasses of composition Ge0.23SbyS0.77-y with an increase of y, except in the material's Vicker's microhardness, which increases with an increasing Sb content. This latter result indicates that the microhardness also depends on Sb2S3 content but seems to be more sensitive to GeS2 content variation. (c) 2005 Elsevier B.V. All rights reserved.