Chalcogenide bulk alloys of Ge10AsxTe90−x (x = 20, 25, 30, 35, 40, 45 and 55) system were prepared by the conventional melt quench-technique. The dc electrical conductivity σ and thermoelectric power (TEP) measurements were carried out in the temperature ranges from 83 to 353 K and from 253 to 353 K, respectively. The variations of both σ and TEP with temperature proved n-type semiconducting behavior of these materials. The current density–electric field characteristics were found to be linear. In addition, the value of negative Seebeck coefficient was decreased with increasing As content. The activation energies, calculated for both electrical conductivity Eσ and thermoelectric power ES, were composition dependent.