The effects of different concentrations of NaCl[0.042%(CK),0.2%,0.4% and 0.6%] on the injury and chlorophyll fluorescence in Acer palmatum seedlings were performed by pot experiment.The results showed that the salt injury of A.palmatum seedlings tuned on mild,moderate and severe respectively when the soil salt contents were set at 0.2%,0.4% and 0.6%.Leaf water content,chlorophyll a and chlorophyll b and the total contents of chlorophyll significantly decreased with the increased salt concentration.At the same time,the anthocyanin content significantly increased with the increased salt concentration by 48.7%,280.3% and 382.7% higher than those of CK respectively.Leaf F_v/F_o,F_v/F_m,Yield,ETR,Φ_PSⅡ and qP significantly decreased with the increased salt concentration,while NPQ significantly increased under low concentration stress and decreased under high concentration stress compared with control.NPQ of the treatments under 0.2% NaCl stress was 33.3% higher than those of CK significantly.It suggested that leaf chlorophyll biosynthesis and photosynthesis were significantly inhibited under salt stress in A.palmatum.While the moderate salt stress could protect photosynthetic apparatus from damage by increasing the energy consumption of PSⅡ reaction center,so the seedling leaves show a certain ability of salt stress tolerance.