PROBLEM TO BE SOLVED: To elucidate a mechanism of the aluminum tolerance in barley, to provide a method for discriminating aluminum-tolerant barley with which even the degree of aluminum tolerance can be discriminated in detail by utilizing the knowledge and to provide a method for utilization thereof. SOLUTION: An amplification pattern when an amplification reaction is carried out with a genomic DNA of the barley using a set of specific two types of primers and/or a set of other specific two types of primers and the amount of a secreted organic acid (citric acid) in the barley exposed to aluminum are used as indexes. Thereby, the aluminum-tolerant barley can be discriminated in detail with a high probability. COPYRIGHT: (C)2005,JPO&NCIPI