In this study, as a promising material for leadfree positive temperature coefficient of resistivity ceramics, (1 -x -y)BaTiO 3 -xBaBiO 3 -y(Bi 0.5 Na 0.5 )TiO 3 (x = 0.001, 0.002, 0.003; y = 0, 0.002, 0.004, 0.006, 0.01) samples were prepared by the conventional mixed oxide method. All the samples were sintered in air atmosphere for 1 h. X-ray diffraction, scanning electron microscope and resistivity-temperature measurement were used to study the crystal structure, microstructure and resistivitytemperature dependence. The results revealed that proper amount of BaBiO 3 doping not only decreased the room temperature resistivity, but also increased the Curie temperature. Its optimal doping content was finally chosen as 0.2 mol%. And with an increase of BNT content, both the Curie temperature and the room temperature resistivity increased. When BaBiO 3 = 0.2 mol%, BNT = 0.6 mol%, the Curie temperature was 153°C and the room temperature resistivity was 1512 X cm. When the BNT content increased to 1 mol%, the Curie temperature increased to 157°C but the room temperature resistivity increased sharply to 4.0 9 10 5 X cm.