A liquid crystal display device and its fabrication method may prevent occurrence of light leakage generated from the sides of a data line. A dummy pattern at sides of the data line with glass powder as an insulation film may simplify the repairing process. A method for fabricating a liquid crystal display device includes a gate electrode, a gate line, a dummy pattern and a first insulation film that are formed on a substrate. A switching element is formed on a portion of the gate electrode and includes a source electrode, a drain electrode and an active layer. A data line formed at a portion of the dummy pattern. A second insulation film is formed on the substrate and has a first contact hole that exposes a portion of the drain electrode. A pixel electrode is formed on the substrate and is electrically connected with the drain electrode through the first contact hole.