The current standard is developed for the purpose of implementation of Environmental Protection Law of the People’s Republic of China, strengthening protection of eco environment and assessing current status and change trend of eco environment of our country. The current standard specifies the indicator system for assessing eco environment and calculation method for each indicator. The current standard is applicable to the assessment of eco environment status and its change trend of counties, provinces and ecological region. Ecological region include ecological function areas, cities/city clusters and nature reserves. The current standard was released for the first time in 2006 and this is the first revision.