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La0.7Ca0.3MnO3(LCMO) thin films have been grown on MgO substrate using the metal organic deposition process. The lattice mismatch between LCMO and MgO is relatively large around 8.14% imposing large in-plane-tensile strain and out-of-plane-compressive strain on the film. Hence the structural, microstructural and electrical properties have been found to be strongly correlated to the strain degree and relaxation. Cross-section transmission electron microscopy observations demonstrate the presence of microstructural defects due to the large lattice mismatch between the LCMO and MgO. In addition to structural and microstructural defects, X-ray diffraction and Raman spectroscopy measurements show the existence of a minor phase of MnO in the film. Magnetization versus temperature measurement show a relatively low Curie temperature around 75 K. The electrical behavior is found to be semiconducting over a large temperature interval. The electrical transport mechanisms have been investigated using the small polaron hopping and variable range hopping models and correlated to their microstructural properties.