The microstructure and electrical properties were investigated for SrTiO3(STO) thin films deposited on Pt/Ti/SiO2/Si(PTSS) and Pt/MgO(PM) substrates by plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD). SrF2 phase existing in the STO films deposited on PM at 500 degrees C influences the dielectric constant, dissipation factor, and leakage current density of STO films. The dielectric constant and dissipation factor of STO films on PTSS and PM at 500 degrees C were 210, 0.02 and 140, 0.07 at 100 kHz, respectively. Leakage current densities of STO films deposited on PTSS and PM at 500 degrees C were about 1.5 x 10(-8) A/cm(2) and 1.0 x 10(-6) A/cm(2) at 2 V, respectively. The leakage current behavior regardless of SrF2 phase in STO films was controlled by Schottky emission with. applied electric field.