Abstract: Barium titanate based dielectric ceramics have been widely used in science and technology, industry and daily life because of their good dielectric and positive temperature coefficient characteristics. Under the demands of emerging fields, it is of great significance to develop dielectric ceramic materials with low Curie temperature and high room temperature resistivity characteristics. Therefore, a ceramic material doped with different concentrations of yttrium oxide (Y₂O₃) with positive temperature coefficient (PTC), barium strontium titanate (Ba_0.7Sr_0.3TiO₃, BST), was prepared by the conventional solid-state reaction. The physical and chemical properties of the samples are observed by X-ray diffraction and scanning electron microscope. The broadband dielectric spectrometer and resistivity-temperature measurement system are used to obtain the dielectric-temperature properties and resistivity-temperature characteristics of the samples, and a four-quadrant model is constructed to analyze the influence mechanism of yttrium (Y) on the dielectric-temperature properties and resistivity-temperature characteristics of the material. The results show that the relative permittivity and Curie temperature increase first and then decrease with the increase of Y₂O₃ content, while the resistivity at room temperature shows an opposite trend. The relative permittivity (> 10⁵) can be significantly increased by doping 0.0008 mol Y₂O₃, and has a lower Curie temperature (34.1 ℃) and a higher resistivity at room temperature (5.6×10⁶ Ω·cm). The synergistic regulation of low Curie temperature and high resistivity characteristics is realized, which broadens the application range of PTC materials.