Abstract: Salicylic acid (SA) has an important regulatory effect on plant growth and resistance physiology under salt-stress conditions. The purpose of this study was to explore the effect of salicylic acid on salt tolerance in perennial ryegrass (Lolium perenne). Under hydroponic conditions, split-plot design was adopted (salicylic acid was used for the main treatment with four levels of 0, 0.25, 0.50 and 1.00 mmol/L; NaCl stress was used for the sub-treatment with two levels of 0 and 250 mmol/L). The results showed that both 0.25 and 0.50 mmol/L levels of salicylic acid could improve the salt tolerance of perennial ryegrass under salt-stress conditions, in that they significantly increase the turf visual quality, total root length, root activity (P0.05), photosynthetic rate, stomatal conductance, leaf relative water content, total chlorophyll content and the proline content (P0.05), and decrease the electrolyte leakage and malondialdehyde content of leaves. However, the salicylic acid treatment at 1 mmol/L had an inhibiting effect on salt tolerance of perennial ryegrass: it decreased the turf visual quality, photosynthetic rate, stomatal conductance, total chlorophyll content and the proline content, and increased the electrolyte leakage and malondialdehyde (MDA) content of leaves. But it had no significant effects on relative water content, root length and root activity (P0.05). By evaluating the influence of salicylic acid at three concentrations on salt tolerance of perennial ryegrass, we reached the conclusion that 0.25 and 0.50 mmol/L salicylic acid promoted the salt tolerance of perennial ryegrass with the former having better effects, but 1.00 mmol/L salicylic acid, on the contrary, inhibited its salt tolerance.