Abstract: Salicylic acid (SA) has emerged as a plant hormone involved in the processes of growth and development, and induced resistance to various abiotic stresses in plants. Studies of the effects of exogenous SA on the growth of Astragalus adsurgens under salt stress will uncover the underlying mechanisms of stress relief. Seedlings of A. adsurgens were treated with 200 mmol/L NaCl and different concentrations of SA (0.2, 0.4, 0.6, 0.8 & 1.0 mmol/L); growth and physiological indexes were subsequently determined. The results showed that, compared with NaCl treatment without SA, exogenous SA ranging from 0.4 to 0.8 mmol/L increased soluble protein content and the activity of superoxide dismutase (SOD) in leaves of A. adsurgens. Soluble protein content increased by 51.9% and 42.6% respectively under 0.6 and 0.8 mmol/L exogenous SA treatments and the activity of SOD increased significantly by 1.58 and 1.68 times under 0.4 and 0.6 mmol/L SA concentrations. Leaf membrane permeability was reduced by SA. SA at 0.4, 0.6 and 0.8 mmol/L reduced leaf conductivity by 19.2%, 26.6% and 18.1% respectively. The photosynthetic capacity of A. adsurgens was also enhanced by exogenous SA treatment. For example, the net photosynthetic rate increased by 1.21 and 1.43 times under 0.4 and 0.6 mmol/L SA treatment. All SA treatments resulted in increased plant height and dry weight in A. adsurgens seedlings. The optimal level of exogenous SA was 0.6 mmol/L. These results indicated that the growth of A. adsurgens under salt stress was enhanced by exogenous SA.