Abstract: Chieh-qua seedlings ‘Feicuida 1’ was selected as the experimental material, the method of hydroponics was adopted and different salt concentrations(0,25,50,75,100,125 mmol·L^-1) were set up to observe and measure the physiological response of chieh-qua seedlings, in order to provide reference for the damage mechanism of alkaline salt stress on chieh-qua seedlings. The results showed that low concentrations of salt stress such as 25,50 mmol·L^-1 had no obvious effect on the seedlings, but higher concentrations of salt stress caused damage to the photosynthetic system of the seedlings, and Y（Ⅱ）,ETR,qP,Fv/Fm increased significantly.In addition, the ROS content ■ and the activities of various antioxidant enzymes were significantly up-regulated under high concentration salt stress.Salt stress also significantly increased MDA content and relative conductivity, which may be caused by excessive accumulation of ROS.Finally, the study also found that the high concentration of salt stress also promoted the significant increase of osmoregulatory substances such as Pro, soluble sugar and soluble protein.In conclusion, the damage of 25,50 mmol·L^-1 salt solution was limited, but the salt concentration of 75 mmol·L^-1 and above exceeded the tolerance range of chieh-qua seedlings.In addition, the chieh-qua could cope with salt stress by increasing photosynthetic heat dissipation, increasing antioxidant enzyme activity and increasing osmoregulator synthesis.