In this literature, bias dependent relaxation and conduction mechanism of grain and grain boundary of Cd1-xZnxS (x = 0, 0.4, 0.8) are discussed with the help of impedance spectroscopy. To get the insight of relaxation and conduction significance in signal transport network, we have simulated the experimental impedance value with appropriate circuit. The simulation provides bias dependent grain and grain boundary resistance and capacitance. It shows that the resistance of grain and grain boundary decreases with the increase in bias and is found to be lesser for Cd0.6Zn0.4S. Using various models we have found that the crystallite size of Cd0.6Zn0.4S is lowest with respect to the other samples and exhibits lower grain and grain boundary resistance with better relaxation. We have tried to correlate the bias dependent grain and grain boundary conduction mechanism with crystallite size using Mandurah model. So, this literature has tried to enlighten the bias dependent relaxation and conduction behavior of Cd1-xZnxS and the impact of grain and grain boundary in the signal transporting network. (C) 2018 Elsevier B.V. All rights reserved.