Abstract: Interdiffusion in the Fe₂O₃-TiO₂ system was investigated by the diffusion couple method in the temperature range of 1323 to 1473 K. The diffusion concentration curves of Ti⁴⁺ cations were obtained by electron probe microanalysis, according to which the Boltzmann-Matano method optimized by Broeder was used to calculate the interdiffusion coefficients. The interdiffusion coefficients almost increased linearly with the mole fraction of Ti⁴⁺ cations increasing, and they were in the range of 10⁻¹²–10⁻¹¹cm²·s⁻¹. The increase of temperature could also lead to the increase of the interdiffusion coefficients at a constant concentration of Ti⁴⁺ cations. It was also found that the thickness growth of the diffusion layer obeyed the parabolic rate law.