This investigation was conducted at the laboratories of Horticulture Departments, Faculty of Agriculture to study the effect of different levels of salinity (NaCl) in the rate and the percentage of seed germination of lettuce, Lactuca sativa L. varieties: Shinshar and Kabous and to determine the seedling response to these levels of salinity with relative to root length, the length of the cold, fresh and dry weight of seedlings. NaCl was used at 0, 50, 100, 150 and 200 mM/l. Resulted showed that a gradual increase in salinity concentrations caused a gradual decline in all indicators studied in both cultivars. However, the plants of Kabous variety were less sensitive to the salinity and also higher than in the indicators studied for seedlings (rate of germination and percent, stems and roots length, fresh and dry weight of seedlings) under salt stress conditions.