Aiming at 3D visual system for ultra-realistic communication, National Institute of Information and Communications Technology (NICT) does research on electronic holography technology. The first period was five years from April 2006 to March 2011. At that period, we developed some prototype systems such as a realtime electronic holography system that captured and reconstructed 3D real objects in non-dark room. The second period is going on from the April 2011 as a five-year program. In this paper, we will introduce some research results of the first period.