The present study was conducted to evaluate the effect of different concentrations of salts on seed germination and seedling growth of Prosopis juliflora. The experiment was carried out in Forestry Laboratory at Sari Agricultural Sciences and Natural Resources University, Iran. The collected seeds were treated with boiling water and H₂SO₄ then left to germinate in controlled growth chamber. Seed were grown under salinity levels 100, 200 and 300 mM of CaCl₂, NaH₂PO₄, KNO₃ and KH₂PO₄. Germination parameters and various seedling growth variables such as root and stem length, seedlings fresh and dry weight were measured after 56 days. Results showed that germination percentage significantly decreased as the salinity level of medium increased. Salinity treatments at 100 mM enhanced the percentage of seeds germination and significantly improved the germination index and seeds stamina. In this study, the best treatment was 100 mM salinity for biomass production of seedlings. For Prosopis juliflora, 100 mM salinity significantly enhanced both germination and biomass production.