Using a cross segregation generation of a 2-row barley variety with a 6-row barley variety, row characteristics of these individuals are exactly judged. As a result, it is found out that the row characteristics show monogenic control. It is also found out that 2-row or 6-row characteristics can be distinguished by using a molecular marker linking to the gene. It is expected that resistance to Gibberella zeae linking to a 2-row or 6-row gene could be distinguished by using the molecular marker.