Abstract: 【Objective】Jasmonic acid (JA) , as an important plant hormone, plays an important role in plants’ response to biological stress and abiotic stress. However, the previous researches on the improvement of plant abiotic stress in JA acid mainly focused on JA to improve the antioxidant ability of plants to improve plant resistance, and its effect on plant water balance was relatively few. Although exogenous JA application is known to enhance plant stress tolerance, the underlying mechanisms involved in this process are still poorly understood.【Method】The influence of methyl jasmonate (MeJA, 1 μmol/L) on water absorption of maize roots under short-term (2h) salt (100 mmol//L) stress was analyzed by applying the methyl jasmonate (1 μmol/L) in an exogenous manner under hydroponics (1/4 Hoaglands nutrient solution) conditions in order to provide a theoretical basis for salt-alkali-resistant maize breeding.【Result】Exogenous methyl jasmonate improved the root biomass and aboveground biomass by 41.32% and 40.69% respectively under salt stress. Moreover, physiological indicator analysis showed that exogenous methyl jasmonate significantly enhanced the physiological indicators of leaves such as net photosynthetic rate (47.48%), transpiration rate, leaf water potential, relative water content of leaf under salt stress; high root hydraulic conductivity (increased by 41.60% compared with non-jasmonate condition) played an important role in maintaining high transpiration rate and relative water content of leaf under salt stress. In addition, exogenous mercuric chloride inhibition test indicated that, under methyl jasmonate conditions, the high root hydraulic conductivity correlated significantly with the aquaporin activity. 【Conclusion】Under salt stress, jasmonate could improve the root hydraulic conductivity of maize by regulating the aquaporin activity in maize roots, thus maintaining high leaf transpiration rate and relative water content of leaf under jasmonate conditions by increasing the water absorption of maize roots.