Most countries having dry and semi dry climate face distilled water shortage. By the same token, desalination of sea water quickly changed into a big source of desalinated water in many areas around the world. Desalination process is a process for purifying sea water for drinking consumption. Desalination process leads to refining salty water and removing salt and minerals from the water. The present study is an attempt to conduct a thermodynamic analysis of MED desalination distillation and its current types (including parallel feed water, forward feed water, backward feed water) to evaluate the effect of some input parameters such as motive steam temperature, concentration, and input water temperature on the efficiency of some output parameters on a desalination system such as GOR, heat loss through waste water, specific heat, and the amount of produced distilled water have been evaluated.