A method for producing a transgenic plant, which comprises: (A) introducing a vector into a plant cell, wherein the vector is a vector for gene introduction into a plant and comprises: a desired gene, and a selectable marker gene comprising a gene encoding an enzyme which synthesizes auxin from an auxin precursor; (B) culturing the plant cell into which the genes are introduced by the vector, in the presence of an auxin precursor and/or an analogue thereof to thereby prepare a redifferentiated tissue, and detecting and selecting the redifferentiated tissues; and (C) culturing the redifferentiated tissue selected in (B) to redifferentiate a plant individual, and a vector for gene introduction into a plant, which comprises: a desired gene, and a selectable marker gene comprising an indoleacetamide hydrolase, iaaH, gene and an isopentenyl transferase, ipt, gene and being free of an tryptophan monooxygenase, iaaM, gene.