The fields of green building and ecological design have much to offer to those who are seeking to improve the ecological impact of schools and school grounds. These well established disciplines are particularly useful to existing schools considering renovations to make them more energy, water, and resource efficient as well as healthier places to work and play, Green building and ecological design principles and techniques are also very effective, of course, if incorporated into the design for brand new school buildings. The major concept of the Eco-school plan is to understand that the school consists of an ecosystem, so the design concept should focus on minimising impact but at the same time maintaining close contact with the environment. T his is becoming the basic concept in applying the Eco-school design to the new 21st century school building. This thesis is an analysis on the methods of application, based on careful examination of case-studies from the U.S.A about detailed plan element and design method, through the following six aspects ; (1) site use plan, (2) green plan, (3) water system plan, (4) materials and recycling of resources, (5) energy use plan, (6) indoor environment plan.