Negative temperature coefficient (NTC) thermistors are those thermal sensitive sensors with their electrical resistivity decreases exponentially significantly as the temperature increases, which are extensively used for temperature control, circuit compensation and precise monitoring. Most of NTC materials’ research concentrate on mixed oxides of transitional elements (Ni, Co, Fe, Cu, Zn etc.) and rare-earth elements which crystallize in spinel structure, perovskite structure. For practical applications, it make a high requirement on the application temperature range and the electrical stability of NTC thermistors. In this thesis, the NTC thermistor materials with low B value and high resistivity applying to in a wide-temperature range were prepared by introducing a second phase of high resistivity into the ceramic materials of low B value and low resistivity. We discuss the preparation process and the effect of high resistivity phase content on the miscrostructure and the electrical properties.