The objective of the present study was to detect the virulence-associated genes of Shigella species in Xicheng district of Beijing and in order to develop the multiplex PCR method for diagnosis.From 2005 to 2007,a total of 95 strains were detected and four sets of primers were applied to amplify ipaH,ial,set1A and set1B genes,respectively.At the same time,a reaction condition was established for the multiplex PCR.Results indicated that the ipaH gene was present in all Shigella strains but the set1A and set1B genes were only present in all Shigella flexneri strains.Moreover,the positive rate of the ial gene in repeated recovery Shigella strains was decreased,and the deletion rate of Shigella sonnei was relatively higher (49%).Results indicated that the diverse distributions of the virulence-associated genes were according to the various distributions of strain types of Shigella.The multiplex PCR method developed a quicker and more convenient way for Shigella strains typing,and it had clinic significance for diagnosis in Shigella species.