PROBLEM TO BE SOLVED: To provide an optimized method for transferring a gene into a mimosa, and to provide a method for creating a transformed plant. SOLUTION: The method for transferring the gene into the mimosa comprises immersing a tissue piece of a juvenile mimosa plant body under a reduced pressure treatment in a liquid infected with Agrobacterium microorganisms containing the aimed gene and carrying out a cocultivation of the tissue piece after immersed in a cocultivation medium. COPYRIGHT: (C)2005,JPO&NCIPI