Ratification of the 1997 Convention on the rights of non-shipping uses of international waterways is considered as a major and important step in development of international Contemporary environmental law. This Development more than anything else, is indebted to to new rules and legal principles. In this convention, many of the legal principles of international environmental law such as" Exploitation and rational and equitable use of resources", the principle " prohibiting damage on the territory of another country" and " The principle of international cooperation" is presented and codified. By studying of legal rules and principles, we can observe course of development of contemporary international law, although, it is obvious that the international environmental law has a long way to reach its proper place. Keywords: International Environmental Law, 1997 Convention on the rights of non-shipping uses of international waterways, Exploitation and rational and equitable use of resources, prohibiting damage on the territory of another country, The principle of international cooperation, International waterways and lakes.