This study was carried out from 9/2022 to 2/2023, at Can Tho University, Vietnam. This study evaluated seedling stages’ salt tolerance in nutrient solution using three electrical conductivity (EC) salt concentrations of 9.38, 12.50, and 15.63 dS/m with fifteen traditional rice varieties. Five traditional salt-tolerant rice varieties at the seedling stage (level 5) at 15.63 dS/m were selected. Furthermore, we evaluated salt tolerance at EC 9.38, 12.50, and 15.63 dS/m in the vegetative and reproductive stages of seven rice varieties (a tolerant variety, Doc Phung, a sensitive variety, IR28, and five rice salt-tolerant varieties were selected at seedling stage). This study showed that an increase in EC concentrations in the soil significantly reduced plant height, panicle/plant, panicle length, a 1000 grain weight, and yield. The addition of 9.38 dS/m EC can distinguish tolerance and sensitive genotypes. The grain yield of sensitive genotypes decreased by 90%–100% at 9.38 dS/m EC, whereas the tolerant genotypes showed