A practical OCT imaging system for ophthalmology became commercially available only five years after the first demonstration of OCT. OCT is thus an epoch-making technique in optics. In such development of the practical OCT system, however, Japanese researchers have been played second fiddle to the research groups in United States, although both basic concept and patent for OCT were proposed for the first time by Japanese researchers. Very recently, the domestic research activities for OCT increased remarkably, because it is necessary to develop many key technologies before OCT is widely applied for clinical diagnoses in the near future. At the present stage, OCT has several shortcomings and technical problems to be solved before its wide application for clinical diagnoses. In this paper, the description is focused on the present status of OCT in Japan as well as development of key technologies for the future OCT.