Thin film of La0.9Sr0.1MnO3/Si prepared by laser molecular beam epitaxy on Si substrate was characterized by means of transmission electron microscopy. The La0.9Sr0.1MnO3 film has an orthorhombic structure and it was polycrystallined with grain size of 10 nm - 20 nm. The grains of La0.9Sr0.1MnO3 displayed a columnar growth normal to the interface. Between the La0.9Sr0.1MnO3 film and Si substrate, two amorphous layers with nanometer dimensions were identified. The formation mechanism of these amorphous layers is proposed on the basis of EDS composition scanning.