Due to the rapid expansion of irrigated agriculture, effi cient use of the limited water resources in arid and semi-arid regions is becoming more and more vital. However, water salinity is a major problem due to its negative infl uence on the yields of many crops. It reduces citrus trees’ growth and causes physiological disorders. Primarily salt-stress lowers net CO2 assimilation, stomatal conductance, and water potential of citrus tree leaves, in addition to accumulation of
excessive concentration of Chloride or Sodium in leaves. A great deal of research indicates that citrus have the genetic potential to be salt-sensitive; however inheritance studies in citrus are scarce. In this paper the adverse of effects of salinity on physiological aspects of citrus are reviewed. The review summarizes the prevailing state of knowledge about the responses and tolerance of citrus trees to salinity.