Modeling of a liquid crystal display (LCD) includes two parts: one is the calculation of the LC director deformation profile inside the cell the other is the LCD optics computation. For the LC director deformation profile calculation, it is usually assumed all the LC molecules within a pixel respond together uniformly to a driving voltage. This one-dimensional (1-D) simulation is a good approximation for most cases. However, due to the finite size of the pixel, the pixel fringe field may drive the LC molecules near the pixel edge to tilt in a direction different from those in the center of the pixel. To understand the detailed LC director structures inside the pixel and their effect on the display performances (especially for the small sized pixel), the two-dimensional (2-D) or sometimes three dimensional (3-D) simulation is required. The 1-D, 2-D and 3-D simulations of the LC director deformation profile will be discussed. For the LCD optics, besides the 4 X 4 matrix method, another alternative method will also be discussed. Finally, examples using the 1-D, 2-D and 3-D LCD simulations to improve the display optical performances will be illustrated.