PROBLEM TO BE SOLVED: To provide a plant increased in the contents of oligosaccharide by activating proliferation of Bifidus bacteria, of the raffinose group, and to provide a method for producing the plant. SOLUTION: The method for producing a plant increased in the content of oligosaccharide of the raffinose group is characterized by comprising subjecting the plant to a dry treatment or a salt treatment. Especially, the dry treatment method is characterized by doing no watering for a fixed period, and the salt treatment method is a method in which a salt solution is added to regular watering.
