The purpose of this study is to suggest environment-friendly assessment elements for the apartment unit plan. For this, the organizing environments of a unit are classified through literature review. Those were five categories of environment: environment of solar system, light, water, green and indoor air Quality. Then, the assessment elements for each categorized environment to evaluate the environment-friendly performance were grasped definitely by examining the applicability of architectural methods or equipment technology. It is expected to suggest not only an assessment tool for evaluation but also a checklist for design in order to develope environment-friendly apartment unit plans.