This paper aims to identify differences and similarities between Japanese and Korean corporate managements in terms of environmental conservation practices and their institutional frameworks. Similar efforts have been made in the countries regarding the introduction of ISO14001 etc. However, there seems to be much difference between their managements, which can be symbolized by different keywords: while Japan often uses "sustainability management", keyword of Korea is "environmental business" or "environmental technology." This difference may partly come from the perception gap toward environmental problems: Japan is eager to attain the goal of greenhouse gas reduction whereas Korea puts emphasis on improving air quality in urban areas to the OECD level. The other possible cause is different industrial structures: Korean industry is much more export-oriented than Japanese one. This paper is expected to contribute to mutual learning for company practitioners, policy makers and policy researchers who are concerned about the practices on corporate sustainability management or environmental business.