Provided is an autostereoscopic three-dimensional image display apparatus. The autostereoscopic three-dimensional image display apparatus includes a display panel including an array of a plurality of sub-pixels, and an optical plate or a line light source, which is spaced a predetermined interval from the display panel at a predetermined inclination angle, wherein an inclination angle of the optical plate or the line light source with respect to a vertical direction of the display panel is determined by an equation.