A TFT that provides an efficient layout, a fabrication method thereof, an LCD device having the TFT, and a fabrication method thereof are provided. The TFT has a gate electrode and source/drain electrodes with an active layer interposed. The source electrodes and the drain electrodes are alternated in a vertical direction and a horizontal direction. Thus, the same source electrodes and the same drain electrodes are arranged in a diagonal direction. Source lines are connected with the source electrodes arranged in a diagonal direction and drain lines are connected with the drain electrodes arranged in a diagonal direction. Since a channel width is formed between the source electrode and adjacent drain electrodes, the channel width can be maximized within a limited area. Also, the source lines and the drain lines are arranged in a diagonal direction, so that an area use rate is maximized.