Abstract: The production and transportation of abscisic acid ABA in potato roots and leaves under different drip irrigation conditions were explored,as well as the regulation of stomata and transpiration by ABA,which provided a basis for physiological water saving under drip irrigation conditions.Five gradient irrigation treatments of 3 000～6 000 m~3/hm~2 were set up to determine the microphysiology of potato leaves and the content of abscisic acid in root leaves under different treatments.The results showed that potato stomatal conductance,transpiration intensity,and net photosynthetic rate were positively correlated with irrigation volume,and showed a significant linear relationship with irrigation volume,while the intercellular CO₂ concentration was the opposite.Leaf abscisic acid ABA plays a certain role in regulating leaf stomatal behavior,but its determination coefficient is only 0.72,indicating that there are other factors or endogenous hormones that can regulate leaf stomatal behavior together with abscisic acid ABA.It shows that leaf abscisic acid ABA plays a direct role in inhibiting potato transpiration.When soil moisture is insufficient,potato produces endogenous hormone ABA through the body’s adaptive feedback system,which reduces leaf transpiration intensity and reduces water loss.