GaSb polycrystalline thin films were prepared on ITO substrate with the method of PVD. By controlling substrate temperatures and thicknesses of GaSb films, surface roughness, grain size, electrical and optical properties were investigated. The preferred orientation of GaSb thin films grown on ITO substrate had changed from GaSb (111) to GaSb (220) under specific growth conditions which had never occurred on glass substrates. GaSb thin films with (220) preferred orientation had higher hall mobility because of less grain boundaries and less defects. The thin films after optimization possess, the absorption coefficients over 104 cm-1, which is desirable in the application of TPV thin film cells.