This experiment evaluated a useful sampling method for studying salt tolerance in rice. Four rice varieties were studied: one salt–tolerant, two moderately salt–tolerant, and one salt–susceptible variety. Rice seeds were grown in seed bed soil for 1 week in tap water and 2 weeks in Yoshida solution. Then, in the salt treatment, seedlings were grown for 2 weeks in a 12 dS m−1 conductive solution, which was made by adding artificial sea water to the Yoshida solution. In the control treatment, Yoshida solution was used instead. After 2 weeks of salt stress, the seedlings were collected and dried. The shoots were then cut into four parts: the sheath part, from 0 to 1 cm including the base (0–1 sheath), the sheath part from 1 to 2 cm (1–2 sheath), the sheath part from 2 cm to the collar (2–C sheath), and the leaf blade. The mineral contents of the salt–tolerant cultivars differed significantly from those of the salt–susceptible variety in 2–C sheath and leaf blades. These plant parts were useful for identifying traits related to salt tolerance. The remaining roots and shoots 2 cm from the base were able to continue growing and produce F1 seeds, which can be used for phenotyping the progeny. The K, Na, and Mg contents and Na/K ratio in the 2–C sheath and the Na content and Na/K ratio in leaf blades can be used as salt–tolerant traits in molecular genetic analyses.