Effective diffusion coefficient in LaCrO3 was determined by transient electrical conductivity based on Fick's second law. The diffusion coefficient of La3+ ion was calculated from the effective diffusion coefficient. The diffusion coefficient of La3+ ion and the activation energy was in agreement with the reported value. The diffusion coefficient of hole in LaCrO3 was also calculated from electrical conductivity and hole concentration. The hole concentration is estimated from the relation between the electrical conductivity and the amount of alkaline-earth in (La,A)CrO3 (A= Sr, Ca). The diffusion coefficient of hole in LaCrO3 was much higher than those of other components in LaCrO3. (C) 2003 Elsevier B.V. All rights reserved.