A method of manufacturing a reflecting substrate in a liquid crystal display device is disclosed, comprising the steps of: (a) providing a substrate having a first metal layer, wherein the first metal layer is formed with at least one soft metal or the alloys thereof; and (b) forming an aluminum nitride layer on the first metal layer. The method of the present invention is capable of forming a rugged, shining, reflective layer on a transflective, or a reflection type TFT LCD with simple steps and low cost.