ObjectiveTo apply a rapid and simple multiplex polymerase chain reaction(PCR) for detecting blaTEM，blaSHV and blaOXA-1 genes in Enterobacteriaceae. MethodsFrom October 2004 to July 2005,171 clinical strains of multiply drugresistant Enterobacteriaceae isolates were collected from three affiliated hospitals of Central South University in Hunan province. Extendedspectrum βlactamases (ESBLs)producing isolates were confirmed by means of phenotypic confirmatory tests as recommended by CLSI/NCCLS, multiplex PCR was used to determine blaTEM，blaSHV and blaOXA-1 genes. ResultsAmong 171 strains of multiply drugresistant Enterobacteriaceae,142 (83.04%) were ESBLs positive by phenotypic detection, 105 of 142 ESBLproducing Enterobacteriaceae isolates were confirmed to obtain positive results by multiplex PCR amplification. blaTEM DNA were detected in 85 isolates, blaSHV DNA in 26 isolates, blaOXA-1 DNA in 10 isolates, and 15 isolates carried  2 or more drugresistant genes.ConclusionMultiplex PCR is a suitable tool which allows the rapid genotypic detection of blaTEM, blaSHV or blaOXA1carrying bacteria from phenotypic ESBLsproducing Enterobacteriaceae.