A stereoscopic image display device includes a display panel, a temporal division plate and a lenticular lens. The display panel includes a gate line, a data line, and a unit pixel of a horizontal pixel structure in which a long side is parallel with the first direction and a short side is parallel with the second direction. The display panel displays a 2D image based on an image control signal. The temporal division plate includes a plurality of shutters disposed on the display panel extending in the second direction. The temporal division plate opens and closes m shutters corresponding to each unit pixel, in a sequence, ‘m’ being a natural number no less than 2). The lenticular lens is disposed on the temporal division plate to convert the 2D image passing the temporal division plate into a 3D image.