Dielectric studies of the quaternary glass system, CdI2-Ag2O-V2O5-B2O3, are reported in the frequency range 100 Hz-10 MHz and the temperature range from room temperature to glass transition temperature. The transport number of the Ag+ ion determined by emf method is 0.98. Conductivity as a function of composition and frequency is discussed. Dielectric studies have been observed as a function of frequency, temperature and composition and explained on the Stevel's model for dielectric relaxation in glasses. The variation of dielectric constant and conductivity with the frequency was explained by correlating the microscopic nature of the ionic conduction process in the glassy system. The activation energy obtained from dielectric relaxation time is comparable with the conductivity suggests the motion of the mobile ion charge carriers are responsible for conductivity and relaxation effect. (c) 2004 Elsevier B.V. All rights reserved.