Caspian sea's legal regiment is regarded as one of the most important problems in I. R. I. foreign policy and as an active agent influencing public peace in our country. The problem has been one of the centric problem focused on by diplomatic system of  I. R. I.and other related countries, but it has not reached to any result. The question intended in the paper is formed as: what kind of agents and variants have been influencing I. R. I. foreign policy when deciding Caspian sea's legal regimen?
   The author has concluded that three interconnected factors including foreign intervening role players, newly independent countries in the area and Russia have acted on I. R. I. foreign policy when deciding Caspian sea's legal regimen and in this manner, I. R. I. has been failed to arrive at its desirable right.