Lanthanum strontium manganite La0.7Sr0.3MnO3 thin films have been grown successfully on Si(001) by metal-organic chemical liquid deposition technique using acetate as the starting materials, and acetic acid and deionized water as the solvent. Crack free, low surface roughness, preferential orientation films with a large MR over a wide temperature range were obtained, which make them very interesting as spin source in Si-based technology. The effects of the high magnetic field and temperature on the electrical, magnetic, and magneto-transport performance were investigated. The relationship between the thermal annealing conditions, microstructure, and the physical properties of the present films were discussed.I