The kinetic structural evolution of the Pb2+-doped La4Ti9O24 ceramics was investigated. Using electron diffraction and Rietveld analysis of the X-ray powder diffraction patterns, we show that the increase in Pb2+ doping results in the structural transition from La4Ti9O24 to a La2/3TiO3-type phase (Ibmm, No. 74). Further kinetic studies of Pb2+ diffusion into La4Ti9O24 ceramics suggest that the La4Ti9O24-La2/3TiO3 phase transition requires an activation energy of 607 +/- 60 kJ/ mol..