Abstract: 【Objective】 To investigate the effect of β-aminobutyric acid on the application of processed tomato under different salt stresses, and to screen the optimal concentration of β-aminobutyric acid. 【Methods】 The effects of β-aminobutyric acid on the agronomic traits and physiological indexes of two processed tomatoes 'Xinhong 49' and 'Tunhe 5501' under different salt stresses were studied by root irrigation at different concentrations of β-aminobutyric acid during the seedling stage of processed tomatoes under different salt stresses. 【Results】 The application of β-aminobutyric acid under different salt stresses could significantly increase the plant height, leaf area, relative chlorophyll content, MDA content and three protective enzyme contents of the two processed tomatoes, and there were significant differences in the index changes between the concentrations of different β-aminobutyric acids. 【Conclusion】 Applying 0.5 mmol/L β-aminobutyric acid can effectively alleviate the salt damage of NaCl to tomato and enhance the activity of its antioxidant system. 1.0mmol· L-1 BABA can effectively alleviate the salt damage of NaHCO₃ to tomato, promote the growth and development of tomato, and improve its salt tolerance.