In terms of the environmental values,the Caspian Sea as the world’s largest inland body of water, is important from national, regional and global points of view.;
The Caspian Sea, because of many kinds of pollution including land-source pollution and increasing petroleum activities (exploration, extraction, transportation and refining) affecting its coastal and marine environments during the last decade, is facing alarming environmental trends.;
Due to the absence of a comprehensive legal framework and lack of commitment of the beneficiary countries in complying with environmental standards and optimal utilization of biological resources of the sea, the enforcement of environmental measures deesnot seem possible.;
The typical instances are the invasion of sea walnuts, reduction in sturgeon stocks in recent years, entry of oil pollutants and the destruction of coastal zones and aquatic habitat.;
Therefore, given the critical environmental status of the Caspian Sea, this marine ecosystem attracted the attention of the United Nations Environment Programme (UNEP) as a result of which the Framework Convention for the Protection of the Environment of the Caspian Sea, known as the Tehran Convention was elaborated.;
Due to the importance of this subject, this article studies the legal aspects of Tehran Convention, explains the strengths and weaknesses of the Convention, and presents strategies for successful implementation of the Convention and promoting the compliance of members with it.