Sr-doped LaCrO3 nanoparticles were prepared by the hydrothermal method with the nonionic surfactant Triton X-100 followed by heat treatment at 1000 degrees C for 10 h. The obtained perovskite nanoparticles had smaller particle size (about 100 nm) and more uniform size distribution than those synthesized by the conventional coprecipitation method. On the other hand, it was identified with the material simulation that the electronic structure change by Sr doping was negligible, because the initially unfilled e(g)-band was not affected by the p-type doping. Finally, the perovskite nanoparticles synthesized by hydrothermal method showed much higher ORR activity by over 200% at 0.8 V vs. RHE than those by coprecipitation method. (c) 2013 Published by Elsevier Ltd.