The effect of variation of A12O3: SiO2 molar ratio through substitution of quartz by calcined bauxite from 0-10% (w/w) on microstructural and thermo-mechanical characteristics of standard porcelain composition has been investigated during firing from 1150-1225 °C/2 h. The fired porcelain bodies were characterized by variation in linear shrinkage, bulk density, apparent porosity, flexural strength, X-ray diffraction analysis and SEM study. The remarkable improvement in thermo-mechanical and electrical properties with well interlocked microstructure were evidenced in electrical porcelain composition based on 7.5% substitution of quartz by calcined bauxite during firing at 1200°C/2 h. © 2017 Scientific Publishers.All rights reserved.