Epitaxial BaTiO3 thin film was prepared on Nb-doped SrTiO3 substrate by coating-pyrolysis process using a mixed solution of barium and titanium naphthenates. The amorphous film pyrolyzed at 470 degrees C was crystallized with high orientation after heat-treatment at 850 degrees C under low oxygen partial pressure. X-ray diffraction theta/2 theta and beta scans indicated that the BaTiO3 film was epitaxial relationship with Nb-doped SrTiO3 substrate. The dielectric constant was approximately 230 at 10(3) Hz and was monotonically decreased with increasing of frequency at room temperature.