The Ph1-xLaxTiO3 powders were prepared by a sol-gel route in the composition range from x = 0.0 to 0.3 in 0.05 increments. The lattice parameters of Pb1-xLaxTiO3 (x = 0.0, 0.05, 0.10, 0.15, 0.20, 0.30) were determined by a high temperature X-ray diffraction, and the intrinsic thermal expansion coefficients were obtained in the temperature range from room temperature to 900° C. The Pb1-xLaxTiO3 compounds (x = 0.10, 0.15, 0.20) in the tetragonal system exhibit low thermal expansion behaviors. As the La content is increased, the phase transition in the Pb1-xLaxTiO3 changes continuously from conventional to diffuse phase transition.