Abstract: Nanocrystalline PbTiO₃ was prepared by using a stearic acid gel method. The synthesis process, crystalline structure and grain sizes of nanocrystal were investigated by differential thermal analysis, thermogravimetric analysis, infrared spectra, X-ray powder diffraction and TEM. The experimental results of dielectric properties of nanocrystal indicate that the dielectric constant ε of nanocrystalline PbTiO₃ is much bigger than that of bulk material. With reducing of grain size, the ε of nanocrystalline PbTiO₃ material increases gradually.