PROBLEM TO BE SOLVED: To provide an aroma enhancing method for continuously enhancing aroma of plants, especially cut flowers by the action of an enzyme exemplified by diglycosidase orβ-glucosidase and decomposing aroma precursors which are produced by microorganisms, and to obtain an aroma enhancing agent to be used for the method. SOLUTION: The plant aroma enhancing method comprises an enzyme treatment process of making the enzyme decomposing the aroma precursors which are produced by the microorganisms act on plants. The enzyme decomposing the aroma precursors comprises a sugar-decomposing enzyme. The sugar-decomposing enzyme is the diglycosidase or theβ-glucosidase. The aroma enhancing agent containing as the active ingredient the enzyme decomposing the aroma precursors is used for the plant aroma enhancing method. COPYRIGHT: (C)2005,JPO&NCIPI