In this article, the authors analyze phases of the development of international environmental law, stating the main features of each, and the relevant international instruments adopted in this area. Special emphasis is put on the importance of the United Nations Conference on the Human Environment (Stockholm 1972), and its formulated principles which serve as the foundation of regulative of this area in the national legislatures of the states that supported the Declaration. The Stockholm Declaration prompted the establishment of special institutions for environmental protection and the constitution of the Regional Environmental Systems. The authors also analyze The Rio Declaration on Environment and Development, which took place in Rio De J...