As a promising material for lead free positive temperature coefficient of resistivity (PTCR) ceramics, La doped (12x)BaTiO 3 -x(Bi 0?5 K 0?5 )TiO 3 [(12x)BT-xBKT] samples with 0#x#0?04 were prepared by a citrate-nitrate sol-gel method. The corresponding gels were heated at different temperatures (500, 600 and 800uC) to study the conditions necessary for the formation of the pure BT-BKT. Single phased perovskite powders with average particles size of 70 nm were obtained by heating the precursor gels at 800uC for 1 h in air. The crystal structure, microstructure and the electrical properties of La doped BT-BKT samples were studied. When the content of La was 0?2 mol.-%, the 0?99BT-0?01BKT ceramic showed the lowest r RT . With increasing addition of BKT, the Curie temperature (T c ) and the room temperature resistivity (r RT ) increased. When the content of BKT was 4 mol.-%, the sample sintered in air atmosphere still showed good PTCR behaviours with T c 5143uC, r RT 51?1610 4 V cm and lg (r max /r min )53?76.