Metal oxide modified Bi2O3 finds the application in metal oxide varistors and as ionic conductors. Electrical properties of MeO-modified Bi2O3 change with MeO modifier and sintering temperature. In this paper we report how to predict Bi2O3 electrical properties using simulation model. Measurements of the electrical response of the modified Bi2O3 oxides were carried out using the impedance spectroscopic technique. As a result an equivalent model of electrical behaviour of modified Bi2O3, described by fractional derivates was proposed. To test the model, the series of simulation were run on computer, and after subjecting the results to verification the equivalent parameters of electrical circuit were determined. Model was elaborated with the view of facilitating the research on metal oxide ionic conductors and varistors.