As many other countries, Algeria is facing a problem of water shortage. The lack of rainfall as well as its variable frequency penalized the government water politics which was maily based on rainfall harness (dams and reserves). Despite the country's considerable potential in sea and brackish water, the Algerian experience is water desalination is strongly associated with the development of hydrocarbon industries and power plants. A certain number of units has been installed and operated in more or less good conditions. The desalination perspective and opportunities are certain, for small units as well as large plants, if we consider the increasing demand and the saline water potential along the 1200 km coast and many underground reserves that are charactrized by a salinity ranging from 2 to 5 g/l.