Medical information system as an infrastructure is required to be developed in Japan in order to
establish, for example, a preventive medicine and better health care, that are indispensable in an aging
society. For this purpose Japanese government is giving financial supports to research projects, where
compact media such as magneto-optical disk and IC-card are supposed to be used. This paper describes
the current activities of these projects and discusses the requirements that medical information system
for wide use should satisfy.
