To improve the salt tolerance of Genovese cultivar of sweet basil (Ocimum basilicum L.) plants, an experiment was conducted to evaluate the impact of certain growth substances (salicylic acid, seaweed extract, dry yeast and moringa leaf extract) on growth, volatile oil percentage and yield as well as chemical constituents under saline water irrigation stress conditions (control, 1000, 2000 and 4000 ppm NaCl). The obtained results revealed that the higher salinity levels (2000 and 4000 ppm NaCl) caused significant decreases in vegetative growth measurements of basil plants compared to control and the lowest salinity level (1000 ppm NaCl). Maximum reduction was observed at 4000 ppm NaCl which showed higher increase of the total phenolics and free proline contents. All recoded parameters were enhanced for plants grown under 1000 ppm NaCl. Seaweed extract was superior than other treatments in enhancing the plant tolerance to salinity which appeared in the significantly increasing of growth and volatile oil content of basil. Phenolics and proline contents were increased with salicylic acid treatment comparing with other ones. The best combination recommended as a result of the current study is treating basil plants with seaweed extract under low salinity level (1000 ppm) for improving the growth and volatile oil parameters.