We use the anodic alumina oxide film as the alignment layer in liquid crystal cell. Nematic liquid crystal molecules can be vertical aligned by controlling the etching time which changing the diameter and aspect ratio of porous AAO films. The maximum polar anchoring strength of the anodic alumina oxide film is 8×10-5(J/m2);therefor the anodic alumina oxide film is a good alignment layer for vertical alignment. By controlling thickness of alumina film, AAO films prepared by the one-step process without any alignment results. However, there are homogeneous alignment results by the two-step process in specific experimental parameter.