Two soybean cultivars (Giza 21 and Giza 35) were exposed to different sea-salt levels in vitro. Growth performance of the plants and biochemical indicators in shoots were measured. Shoot height (SH), leaf numbers (LN) and seedlings fresh weight (SFW) were decreased in both cultivars with an increase in the sea-salt concentration. Whereas, root length (RL) and seedlings dry weight (SDW) had insignificant changes due to salt stress in both cultivars compared to control. Salinization of seedlings has shown to increase sodium (Na⁺), nitrogen (N), and phosphorus (P) ions accumulation in both cultivars. Contrary, K⁺ and Ca²⁺ ions percentages increased in Giza 35 cultivar upon sea-salt stress of 4000 ppm, after which their percentages decreased to same level of the control. Notable, salinized seedlings of Giza 21 cultivar showed insignificant changes in K⁺ and Ca²⁺ ions percentage under sea-salt stress. For organic osmolytes, proline increased in both cultivars under high sea-salt levels. The enzymatic activity of catalase (CAT) was significantly decreased in Giza 21 cultivar under 6000 ppm. However, insignificant changes in its activity were recorder in cultivar Giza 35 under sea-salt stress. Superoxide dismutase (SOD) activity was decreased in both cultivars under high sea-salt levels. Interestingly, The ascorbic acid oxidase activity in Giza 35 increased under sea-salt level of 2000 ppm followed by a decrease under 4000 ppm and finally the its activity significantly increased under high sea-salt stress of 6000 ppm. On the other hand, salt stress did not induce significant changes in AAO activity in Giza 21.