SrTiO3 (STO) films were deposited onto the ptype Si substrates by metalorganic decomposition (MOD) technique. The dielectric and interface characteristics of STO with a metalinsulatorsemiconductor(MIS) structure were investigated. The results showed that the dielectric constant was about 105 and the dissipation factor was lower than 001 for our STO films at a frequency of 10kHz. The excellent dielectric properties were attributed to the polycrystalline structure with good crystallinity. The fixed charge density Nf and the interfacetrap density Dit were calculated to be about 15×1012cm-2 and (14—35)×1012cm-2eV-1, respectively. Both Nf and Dit were mainly connected with an interface layer with low dielectric constant formed at the interface of Si/STO.