The last decade witnesses a growing interest in the application of the Spectral Induced Polarization (SIP) method in hydrogeological and environmental investigations. This is may be inspired by the fact that both groundwater and electrical current move via interconnected paths through rock matrix. However, application of the SIP method in vadose zone studied has received minimal attention, and models for its mechanisms in Earth material primarily focus on water-saturated materials. Therefore, knowing the dependence of electrical spectra parameters on saturation is clearly necessary in order to reliably interpret SIP measurements in vadose zone. This paper tries to add to the knowledge of the effect of water saturation on A.C. electrical current and its parameters on fully and partially saturated Taref sandstone samples (Western desert, Egypt). All of the sandstone samples under this study displayed clear relaxation type phenomena at fully saturation status, and an obvious dependence of SIP parameters on water saturation. Generally, the real part of the conductivity depends mainly on the saturating fluid conductivity as well as porosity of the rock, where the characteristics of the electrical double layer at the matrix-fluid interface have the major influence on the imaginary part. An increase in resistivity and a reduction in real conductivity with reducing saturation were noticed; where a non-linear behavior of both phase angle as well as quadrature conductivity with saturation is clearly observed. Moreover, two water saturation reflection points seem to dominate the electoral spectra behavior with changing saturation over the studied samples. The strong dependence of SIP parameters on water saturation clarified in this study, confirmed the potential value of SIP method for groundwater modeling as well as groundwater contamination studies due to pore throat sizes and distribution influence on relaxation behavior