Polyimide films irradiated with linearly polarized deep UV (LPDUV) light can align liquid crystals perpendicularly to its polarization direction. We report an experiment using near edge X-ray absorption fine structure (NEXAFS) spectroscopy with high surface sensitivity to elucidate the LC alignment mechanisms by total electron yield (TEY) and partial electron yield (PEY) methods. The dichroic ratio of O K-edge pi* peak intensity, originated from C=O bond, shows different UV exposure dependence for TEY and PEY cases. We can conclude that the LPDUV irradiated film possesses the depth dependence of anisotropy.