Silicon (Si) is not considered as an essential plant nutrient, but its beneficial effects on plant growth and yield have been reported. Silicon nutrition seems to be useful in alleviating harmful effects of various stresses, including salinity on certain plants. Salinity is one of the most important abiotic stresses negatively affecting pistachio production in most parts of the world such as Iran. Considering the economic importance of pistachio production as a strategic product, it is important to find out proper management approaches to increase plant tolerance to salinity. In this soilless culture experiment, the effect of foliar-applied Si in the form of mineral and complexed with amino acids histidine (His) and methionine (Met) on alleviating salt-induced damages on pistachio rootstock ( Pistachio vera L. cv. Badami zarand) was investigated. Pistachio seedlings were grown in pots containing a mixture of sand and perlite (2:1 v/v) in greenhouse and exposed to different levels of salinity (0, 40, 80, 120 mM NaCl) for 70 d. Different Si solutions including potassium silicate, and complexes of Si with histidine (Si-His) and histidine plus methionine (Si-His-Met) were applied as foliar spray at 3 times with 20-d intervals. A Si-free solution containing only His free of Si was used to distinguish the effects of Si and amino acids. The control was considered free of Si and amino acids. Salinity resulted in significant decreases of the measured vegetative traits including stem length and diameter and fresh and dry weight of shoots and roots. Salinity stress significantly increased the ion leakage, malondialdehyde (MDA) content, sodium (Na) concentration and proline content of the leaves, and caused a significant decrease i the leaf relative water content, total chlorophyll concentration and fluorescence chlorophyll. In addition, a significant increase in the leaf activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) enzymes was observed. Salinity also enhanced leaf protein content. In contrast, foliar application of Si resulted in higher leaf relative water content and chlorophyll concentration and lower ion leakage and MDA content of the plants exposed to salt stress. Based on the results, Si applied from the source of potassium silicate was effective in reducing the damage caused by salinity stress on pistachio rootstocks via improvement of certain plant physiological characteristics. Keywords : Silicon, Amino chelate, Salinity Stress, Antioxidant Enzymes, Pistachio