(Ba1-x, Sr-x)TiO3 (BST) films were deposited on Pt/Ti/SiO2/Si substrates with various Ti buffer layer thicknesses by metalorganic chemical vapor deposition. The deposition rate and surface morphologies of the BST films were strongly dependent on the titanium buffer layer thickness. The deposition rate of BST films linearly increases with increasing Ti thickness. Titanium diffusion through the platinum bottom electrode played an important role as a nucleation site for BST growth. The 50 nm thick BST films deposited on Pt/Ti/SiO2/Si substrates with a Ti thickness of 50 nm have a dielectric constant of 190 and a dissipation factor of 0.025 at 100 kHz. The films showed symmetrical J-V characteristics with respect to the bias polarity and leakage current density of 8.0x 10(-7) A/cm(2) at an applied voltage of 1 V. The optimal thickness of the Ti buffer layer in Pt/Ti/SiO2/Si substrates is important to obtain good electrical properties of BST films.