The effects of different concentrations of salicylic acid (0.3, 0.6, 0.9 mmol/L) on the growth and physiological characteristics of tall fescue under 250 mmol/L NaCl stress were studied by pot experiment. The results showed that salicylic acid (SA) could increase the relative growth rate under salt stress, and the relative growth rate with 0.6 mmol/L SA for 15 d was 92.7%, 54.9% and 46.3% higher than that in treatments without SA, with 0.3 mmol/L SA and with 0.9 mmol/L SA, respectively. Spraying SA could increase the relative water content of leaves under salt stress, and the treatment of 0.6 mmol/L SA showed the highest water content. The electrolyte leakage rate in treatment with 0.6 mmol/L SA was the lowest, which was 27.4%, 11.4% and 9.0% lower than that in the treatments without SA, with 0.3 mmol/L SA and with 0.9 mmol/L SA, respectively. The content of chlorophyll with 0.6 mmol/L SA was the highest. After 25 d of SA treating, the MDA content in 0.6 mmol/L SA treatment was 20.63% lower than that in treatment without SA. The content of H2O2 in 0.6 mmol/LSA and 0.9 mmol/L SA treatments was the lowest, which was respectively 17.95% and 15.38% lower than that in treatment without SA. The SOD and APX activities of 0.6 mmol/L SA treatment were respectively 155.56% and 77.38% higher than that in treatment without SA. According to the changes of the above indexes, the effect of 0.6 mmol/L SA is the best to alleviate salt stress.