Seedlings of Brazilian, Spanish and Balady sour orange rootstocks were studied for their tolerance to five salinity levels : tap water (control), 1000, 2000, 3000 and 4000 ppm of NaCl, CaCl₂ and MgCl_{2 .}. All growth parameters of Balady, Brazilian and Spanish seedlings measured were significantly affected by salinity levels. Brazilian sour orange seedlings gave the highest values of all growth parameters such as stem length and diameter, leaf number per plant, leaf area and dry weight of top and roots followed by Balady sour orange and Spanish seedlings, respectively. Chlorophyll a, b and its total value decreased as salinity increased in irrigation water. In contrary, free proline amino acid, soluble and non soluble sugars were increased with increasing saline water. Moreover, Brazilian rootstock had higher amount of chlorophyll, proline and soluble and non soluble sugars than those recorded for Balady and Spanish rootstocks. On the other hand, leaf tissue analysis showed that increasing the salinity level in irrigation water caused a significant increase in N, Ca, Mg, Na, Cl and Fe values, but decreased content of P, K, Mn, Zn and Cu . Moreover, root Ca, Mg, Na, Cl, and Fe, contents were increased with increasing salinity level, while, N, P, K, K, Mn, Zn, and Cu values were decreased . Brazilian seedling tended to contain the lowest Na, and Cl concentrations when compared with those of both Spanish and Balady seedlings . This may be explain why Brazilian is the most tolerant rootstock to salinity .there for, The three rootstocks can be arranged in the following descending order due to their salt tolerance: Brazilian> Balady> Spanish.