Abstract: According to the sequence of the nuc gene, which encodes the thermostable nuclease （TNase） of Staphylococcus aureus （S. aureus）, a pair of oligonucleotide primers which are special to the sequence of nuc gene were designed and synthesized. Using the genome DNA of the clinically isolated strain of S. aureus SA. m0109 as template, the fragment flanking nuc gene was amplified by Polymerase Chain Reaction （PCR）. The expected size fragment was obtained and was cloned into the plasmid pGEM-T. The recombinant plasmid of pGEM-NUC was identified by restriction enzyme analysis, PCR and sequencing, which proved completely its validity.