A systematic study was made of the semiconducting chalchogenide glass system Ge20SbxSe80−x with 5 < x < 40 at.%. The dependence of the electrical conductivity of bulk specimens on the temperature revealed the role of both the Sb content and the annealing temperature. X-Ray examination as well as differential scanning calorimeter analyses (DSC) were helpful in the identification of the structural changes. The characteristics of the lone pair amorphous semiconductor seem to account for the observed dependence of the localized density of states, N(E), at the Fermi energy, on the annealing temperature