Alignments of liquid crystal are obtained. A transparent magnetic thin film provides a homeotropic alignment of liquid crystal molecules. Or, a homeotropic or homogeneous alignment having an adjustable pretilt angle is further obtained through rubbing the transparent magnetic thin film. The present invention has a simple procedure with a low cost. The present invention is used in equipment with a plasma source while providing high transmittance, hardness and insulation. And the transparent magnetic thin film has potential uses in the applications of non-contact multi-domain alignment without extra procedure for alignment treatment.