It is possible to consider the environmental accounting in terms of national, regional and/or corporation based. So the concept is a kind of an umbrella term that includes accounting at different levels like national or corporation. The main approach in understanding of environmental accounting is to include changes in the natural environment into the national/regional accounts or corporate balance sheet. However, this study attempts to clarify the term of environmental accounting in 18 terms of corporations. Its orientation is trying to become practical not merely academic. In doing so, we focus on environmental accounting for internal managerial decision-making rather than accounting for reporting to external shareholders. Environmental accounting defines as the process of environment-based categorization of corporate activities, collecting, analyzing and then monitoring this environment-related activities, then put all these information into corporate balance sheet (eco-balance sheet) to help an organization’s decision-making.