A three-dimensional display for the viewer to watch through glasses is provided, wherein the glasses have two lenses and the polarized directions thereof are perpendicular to each other. The three-dimensional display includes a display panel and a liquid crystal phase modulator. The display panel, suitable for displaying an image, has a plurality of pixels arranged in array and a polarizer having a transmission axis, wherein the polarizer disposed between the pixels and the glasses. The liquid crystal phase modulator suitable for providing phase retardation includes a liquid crystal layer and an alignment layer adjacent to the display panel. An included angle between an alignment direction of the alignment layer and the transmission axis is substantially equal to n×45 degrees, wherein an absolute value of n is an integer. The liquid crystal phase modulator adjusts a phase of the image and then outputs an image with three-dimensional information.