The article discusses the periods of environmental education (EE) development in connection with internal social and global international influences, mainly the effect of the First United Nations Conference on Human environment in Stockholm 1972, the 1992 Earth Summit in Rio de Janeiro and the 2002 Earth Summit in Johannesburg. It pays attention to the impact of the social background and the role of science and pedalogical research on the different stages in the curricular and textbooks development. The school subjects contents and educational technologies also evolved towards student-centered interactive education in school and out of school. A system of EE from nursery to postgraduate and lifelong education was developed in 1984 and a great part of it has been introduced in the different educational stages since then. After 1989 more than 132 NGOs and communities on ecology and environmental education were established and many others incorporated environmental education aspects in their activities. Still there are many unsolved problems in EE.