Abstract: ObjectiveTo investigate the differences among the three fast-detect PCR methods in their specificity and sensitivity for the detection of Listeria monocytogenes(LM).MethodsBased on the sequence of LM virulence geneiap and prfA,five pairs of primers were designed for each of the three PCR.ResultsAll the primers showed high specificity.The sensitivity of the nested-PCR got as high as 10² cfu/ml,which was more sensitive than the single-PCR(10³ cfu/ml)and the multiplex-PCR(10⁴ cfu/ml).ConclusionMultiplex-PCR has more advantages in specificity.However,nested-PCR was more sensitive than single-PCR and multiplex-PCR obviously.Therefore,the primary health and quarantine departments should choose a suitable method according to their situations and the purpose of supervision work.