In this study, the effect of Bi2O3 doping on microstructure and electrical properties of ZnO-V2O5-Mn3O4 semiconducting ceramics was investigated through the sintering temperature as low as 825 degrees C. Analysis of the microstructure revealed that ZnO-V2O5-Mn3O4-Bi2O3 ceramics consisted of major ZnO grain, and minor such as Zn-3(VO4)(2), ZnV2O4, VO2, and BiVO4. As the amount of Bi2O3 increased, the densities of sintered pellets increased from 5.55 to 5.46 g/cm(3), and the average grain size decreased from 5.6 to 3.9 lm until the amount of Bi2O3 reaches 0.05 mol%. The breakdown field increased from 4835 to 10,317 V/cm until the amount of Bi2O3 reaches 0.025 mol%. The highest nonlinear coefficient was obtained at the ceramics doped with 0.025 mol%, reaching 46.6. The dielectric constant decreased from 1324.5 to 544.7, and dissipation factor decreased from 0.506 to 0.176, until the amount of Bi2O3 reaches 0.05 mol%.