In the University of Tsukuba, PACS research is being carried out with a special emphasis on the reporting system. The radiological diagnostic system in Japan is not sufficiently developed and the number of diagnostic radiologists in Japan is not as large as in many European countries (M. Akisada, Present status of PACS activities in Japan. Med. Inform. 13 (1988) 289-293). With recognition of this fact, PACS research in Japan should also focus on the reporting system. Recently, the first PACS workstation was installed in the Department of Radiology of the University Hospital, but it has not yet been put to clinical use. Reports can be made on this workstation while viewing the properly provided digital images of MR and CT. As to the concepts of the reporting system, there are three important points. The first one is the double check system to maintain the standard quality of diagnostic performance. This system is expected to provide proper training and education to students and young doctors (S.E. Selzer, S.J. Hessel, P.G. Herman et al., Resident film interpretations and staff review. Am. J. Radiol. 137 (1981) 129-133). The second one is to develop a transcriber workstation, through which reports are easily handled as routine work. The last point is to provide a well-organized diagnostic coding system. For this purpose, a modified IRD (Index for Radiological Diagnosis, by the American College of Radiology) is assumed to be one of the best choices.