Environment’s problems have pervasive and lasting consequences not only on this generation but also on next generation. Conversion of environment’s effects on human’s life will appear so soon. One of the most important environmental crisis that we face with is the Caspian sea crisis. The Caspian Sea as the largest saline lake in the world has a sensitive and fragile ecosystem. although saline lakes are very important for environment but international law didn’t pay attention as much as it did to fresh water .In this paper, we examine what is the best solution for the Caspian Sea crisis? can international law solve this problem? But international law can’t solve these problems all alone but it can be concluded according to other states experiences and getting help from political. So, we first examine saline lakes under international law and next studying about the Caspian Sea and similar experience especially the great lake and at last examine the best solution.