Laboratory and pot experiment were conducted Through two successive seasons,(1995 –1996 ), to study the effect of four levels of salinity(0,1500,3000and 4500 ppm) on seed germination and survival percentage, growth characters and essential oil percentage of four varieties of Ocimum basilicum plants ( Ocimum basilicm var. Odoratus(v₁), var. Alba(v₂), var. Thyrsiflorum (V3)  and var.Purpurascens(v₄) ). The highest seed germination percentage was noticed with variety purpurascen on the level 1500 ppm of salinity during first and second season,while maximum survival Percentage resulted with Thyrsiflorum(v₃) with the same previously level of salinity in the first season, but was with purpurascen (V4) in the second one. Meanwhile, the vegetative growth of various varieties recorded very widely variation by salinity treatments. V4 gave the highest volatile oil percentage in the two cuts during both seasons, and there were insignificant differences between the other varieties. Regarding to salinity effect found that both of 3000 and 4500 ppm decreased essential oil percentage, but 1500 ppm increased it significantly in comparison with control, and locking for the interaction between salinity and varieties, noticed that V4 with 1500 ppm level resulted the highest essential oil percentage, during first and second cut in both seasons.              The highest level of oil yield  (ml)/plant was noticed at V3 during the two seasons of first cut, but it was resulted by V3 in the first season, and by V4 in second of second cut. All of used salinity levels caused a decrease in oil yield, meanwhile the lowest one was observed with highest applied level (4500ppm). According to interaction between variety and salinity, the largest amount of oil yield/plant was resulted with V4 and applied level of 1500ppm during the successive two season of first and second cut.