Abstract:In plant cells, Ca2+ as a secondary messenger, can affect cellular metabolism through the activation of Calciumdependent protein kinases (CDPKs). CDPKs are wildly distributed in plants and algae, and also in some protistas. They are the most deeply studied kinases in plant tissues. The phylogenetic distribution, subcellular localization, structural characteristics, biochemical properties and physiological functions in plant cells are reviewed. The research perspective in this field is also discussed.