We have designed a single gap transflective liquid crystal display (LCD) using an in-plane switching mode, where the rotating angle of the LC director between electrodes, and above electrodes, is 45 degrees and 22.5 degrees in average, respectively. Optimization of the cell structures such as electrode structure, cell structure, physical properties of the LC and the LC cell retardation value have been perform to obtain a low-power transflectiue LCD with a single gap structure and a single driving circuit.