Abstract: The Aral Sea was once the 4th largest lake in the world and shrank to about 10% nowadays,because of far from the world’s major oceans and the fragile hydrological system.Several questions are urgent to be answered,namely,how the Aral Sea formatted,what it has undergone,and what’s the evolution mechanism,which have always been a concern of related scientists all around the world.The Aral Sea basin (the Amu Darya and the Syr Darya),a main component of the complete Asian water tower system centered on the Qinghai-Tibet Plateau,which came into being after uplift of the Qinghai-Tibet Plateau,the retreat of the Neo-Tethys Sea,and under the impact of regional and global factors such as the global climate cooling and sea level decline.The Aral Sea system has maintained a relatively stable level in water surface area and hydrology pattern from the formation to the middle of the last century.It has only experienced extensive exploitation and utilization of water resources,resulting in the shrinking surface water area,the increasing exposed dry lake bed and frequent salt dust storms in the context of climate change from the second half of the 20th century,which have caused the crisis in the Aral Sea basin.

Key words: Aral Sea, formation process, evolution mechanism, crises, Tibetan Plateau, arid Central Asia