Three sets of water samples with Neiseria gonorrhoeae and one without bacteria were prepared as quality control materials of PCR.Several laboratories in Guangdong province were asked to determine the presence or absence of Neiseria gonorrhoeae by application of PCR.Twenty three participating laboratories had returned the results. False positive PCR results were 17 6%, Positive PCR results were reported for 15 7% of the samples with 10 CFU, for 27 2% with 10 2 CFU and for 53 9% with 10 3 CFU,respectively. The results of the study show that the implementation of an effective system for monitoring false positive and false negative is required before the PCR can be used reliably in routine laboratories in the diagnosis of Neseria gonorrhoeae.