An experimental study of p-silicon (Si)/La0.7Sr0.3MnO3 (LSMO) junction in which the LSMO and silicon are separated by a thin interfacial silicon dioxide (SiO2) layer has been fabricated. Two type of SiO2 layer has been discussed here e one is native oxide and another one is thermal oxide. The thermal SiO2 film is grown on Si by annealing it at 800 degrees C in oxygen atmosphere. The LSMO film of about 64 nm thick has been grown on SiO2 at 800 degrees C substrate temperature in 10(-1) mbar oxygen pressure by Pulsed Laser Deposition technique. The LSMO/SiO2/Si heterostructure exhibits MOS diode-like behavior with all type of possible current flow mechanisms (such as thermionic emission, tunneling, recombination degeneration, etc.) through the heterojunction. The high field Fowler-Nordheim [ln(J(FN)/E-2) vs 1/E] plot at different temperatures confirms that the dominating transport mechanism across the heterostructure is tunneling. The junction resistance changes under magnetic field and the junction magnetoresistance is found to be similar to 31% with 1T applied magnetic field at room temperature at a bias voltage of 2.2 V. The capacitor-voltage characteristics confirm the presence of trap charges. (C) 2011 Elsevier B.V. All rights reserved.