Salinity is one of the most important problems in the arid and semi-arid areas. Therefore Known of plant reflection to salt contents could be a suitable way to more salty waters exploit. Sesame(Sesamum indicum) is an important oil seed plant in semi-arid area such as Isfahan. This plant is rated as moderately salt tolerant and at future it could produce profitable crops on saline soils. It is faintly more tolerant of salinity than wheat. An experiment was carried out to determine the effects of salinity levels on germination indexes, morphological characters,yield and yield components, oil and protein contents of ten sesame cultivars(Karaj1, Darab14, Jiroft13, Safi Abad, Borazjan5, YellowWhite, Oltan, Precocious Felestin, Isfahan, Abpakhsh) at formative stage using 0, .0.5, 1, 1.5, 2 and 2.5 percents NaCl in lab and field. The results showed significant differences among the cultivars for all traits at different salt levels.in lab experiment: Germination percentage and rate, root and shoot length, root and shoot dry weight were investigated. The results showed that the highest values for the investigated traits were obtained from variety Abpaksh, while they diminished with increasing water salinity in all cultivars. Among the varieties, the highest germination percentage and rate, root length, shoot length and root dry weight at 2.5% salinity, were determined from Abpaksh, with 49.5%, 10.2 seed per day, 0.85 cm, 1.65 cm and 0.25 mg respectively, and Isfahan in shoot dry weight with 0.32 mg. Moreover, Abpaksh gave the higher average in more indexes, at whole salinity levels. The seedling growth of varieties was inhibited by 1-1.5% salinity, although they showed varying responses. At the first development stage, the root growth of sesame was more negatively affected compared to shoot growth by water salinity. In field experiment: Increase of salinity concentration decreased growth of sesame cultivars and their traits such as: plant height, dry weight of root and shoot, capsule number per plant, grain number in capsule, 1000 grain weight, oil and protein content. Ab pakhsh cultivar identified as the most tolerant and Oltan as the most sensitive cultivar at germination stage. Oltan cultivar identified as the most tolerant and Yellow white as the most sensitive cultivar to morphological characters. Safi aabad cultivar identified as the most tolerant and Yellow white as the most sensitive cultivar to yield components. Oltan cultivar had the most and Borazjan5 the less content of oil and protein. Because salinity reduces germination and delays emergence, sesame stands tend to be irregular and crop yield is depressed. However, some genotypes are less affected by salinity than others. Key words : Salinity, Sesame, Germination Indexes, Morphological Characters, Yield and Yield Components, Oil and Protein Content