Salinity poses a significant abiotic stress factor that exerts detrimental effects on plant growth during germination and early seedling stages. The global prevalence of high salt concentration has transformed salinity into a serious problem, impacting vast expanses of land worldwide. This experiment aims to examine the effects of various concentrations of Sodium chloride (NaCl), including 200 mM, 150 mM, 50 mM, and 50 mM, on the seed development at early stage and germination of different cultivars of soybean to determine the variety with the highest value of tolerance, while exploring the underlying mechanisms responsible for salt tolerance in these plants. The parameters considered for measurement included relative injury rate, mean germination time, germination percentage, water uptake percentage, seedling height reduction, seedling biomass, and salt tolerance. Among these parameters, seedling height was highly affected with up to 72.58% reduction in 200 mM, followed by fresh weight and water uptake percentage. The parameters with minimum changes from 0 mM to 200 mM were mean germination time and relative injury rate. By assessing these parameters, a comprehensive understanding of the effects of salinity on soybean genotypes can be obtained. In conclusion, the study suggests that seedling traits are a reliable way to identify genotypes with increased tolerance to salinity stress by farmers according to the salinity situation in their soils.