A method of displaying a three-dimensional (“3D”) image, the method includes determining a shutter electrode of an unit part included in a shutter panel as a left-eye electrode and a right-eye electrode, the unit part including ‘n’ shutter electrodes (herein, n is a natural number), selectively driving the left-eye electrode and the right-eye electrode as an opening part based on an image displayed on a display panel to transmit light through the opening part, and providing light transmitted through the opening part with an observer's two eyes through a lens plate, the lens plate including a plurality of lenses.