In order to establish yeast cells that produce leucocin A, a bacteriocin, the 117 bp leucocin A gene with start and stop codons was synthesized and cloned in pAUR123, a yeast vector. Transformed yeast cells showed antibacterial activity against Bacillus subtilis. The leucocin A gene was confirmed by means of PCR methods with plasmid prepared from transformed yeast cells as template and two leucocin A-specific primers. In this results, yeast cells that produce mass amounts of bacteriocin to use as food preservative or antibiotics were established.