The ionic conductivity of the 0.5 AgI(.)xSbI(3)(.)(0.5 -x)Sb2S3 and 0.5 AgI(.)xPbI(2)(.)(0.5 - x)Sb2S3 glassy systems with a constant silver concentration has been investigated. It was found that the Ag+ ion transport is closely related to the heavy metal iodide content. The conductivity activation energy decreases from 0.38 to 0.28 eV, and the room temperature conductivity increases by a factor of 100 with increasing x. A structural model based on available neutron diffraction, EXAFS and I-129-Mossbauer spectroscopy data was proposed to explain the observed phenomena.