The pho5 gene of S. cerevisiae encodes the repressible acid phosphatase(rApase) which is regulated by the concentration of Pi in a medium. Introducting the pho5 gene into tobacco plants and allowing sebsequent expression under the control of CaMV 35S promotor, it is expected to make transgenic plants resistant to Pi deprivation in acidified soil. For this purpose, plasmid pBSW1 was constructed by the insertion of 1.5 kb DNA fraagment containing the entire open reading frame of pho5 gene into T-DNA region of pBKS1-1, a binary vector. Tobacco cells were transformed by co-incubating with A. tumefaciens cells carryng pBSW1. Transformed cells were regenerated into natural plants which have the T-DNA region of pBSW1 in their genome.