The electric conductivity of polymer-derived amorphous silicoaluminum oxycarbide was measured as a function of temperature and pressure. The material exhibits typical amorphous semiconducting behavior, following band-tail hopping process. The characteristic temperature of the BTH process increases with increasing pressure, indicating that the density of states in the band-tail is changed by applying pressure. The piezoresistive stress coefficient of the material was calculated and increased with increasing temperature, which is different from other materials. It is found that such increase is due to the change in the characteristic temperature.