The important trend of display technologies is to display real-existing three-dimensional (3D) images. More and more attentions are now paid on 3D electro-holographic display (3D-EHD) because of its capability of reconstructing real-existing 3D images. Some researching works associated with 3D-EHD are described in this paper, including theories and methods of computer holography, algorithms for calculating computer-generated hologram (CGH) of true-color 3D object, characteristics analysis of the spat...