Electrical properties of La-(Fe,Mn)-codoped positive temperature coefficient of resistivity (PTCR) BaTiO3 ceramics were studied by combining their diffuse reflectance measurements and electron spin resonance (ESR) spectroscopy. La-(Fe,Mn)-codoped samples showed high durability to reducing atmosphere. It is assumed that Fe and Mn ions segregated in the grain boundary contribute to the density of surface acceptor states, meanwhile localizing electrons in a form of Ti3+ and stabilizing the chemisorbed oxygens through La3+-Mn-3+,Mn-4+ or La3+-Fe3+ pairs. In addition, ESR signals of Fe3+ in annealed samples was intensified above Curie temperature (T-c), indicating that Fe ions still maintained its high valence states (Fe3+) in the grain boundary even after annealing in reducing atmosphere.