A pot experiment was carried out during two successive seasons to study the effects of varieties of basil (Ocimum basilicum var. odoratus, Ocimum basilicum var. alba, Ocimum basilicum var. thyrsiflorum and Ocimum basilicum var. purpurascens) and soil salinity levels (0, 1 500, 3 000 and 4 500 mg kg-1) on oil content and its composition. Essential oil (%) and oil yield (ml plant -1) were significantly increased by using 1 500 mg kg-1 of soil salinity compared to control. On the contrary, there was significant decrease in this regard by using higher level of soil salinity, at 4 500 mg kg-1. The major components of the essential oil of basil varieties were eugenol and linalool in the two cuts. Soil salinity treatments at 1 500 and 4 500 mg kg-1 levels increased the content of linalool and, on the contrary, there was a decrease in eugenol content by using 1 500 and 4 500 mg kg-1 of soil salinity in Ocimum basilicum var. purpurascens.