As a second messenger,Ca²⁺ is involved in signal transduction pathways related to various responses to abiotic and biotic stress in plant.The specific calcium signal in plant cell is actived by different stress via stimulating calcium channel on the plant plasma membrane,then transformed to Ca²⁺ sensing proteins,such as calmodulin(CaM),Ca²⁺-dependent protein kinases(CDPK) and calcineurin B-like protein,etc.,which induced a series of physiological and biochemical processes of plant cell to the stress.Drought stress is one of the most serious abiotic stresses in the earth.Ca²⁺ signal plays a pivotal role on response to drought stress,by regulating stomatal movement,water channel protein(aquaporin,AQP) and antioxidase activity to reduce water loss and drought damage,increasing water use efficiency.Furthermore,Ca²⁺ has some ecological functions.In this paper,we also summarize the new progress Ca²⁺ signal and its regulation for response to drought stress,and propose simple prospect in the future.