Abstract: Objective To analyze the gene sequences related to multidrug resistance in Shigella spp.Methods Genomic DNAs were extracted from the sensitive strain(Z 23)and the induced multidrug resistant strain(YD).The gene fragments(Y16B3,Y16B8,Y16A11)probably related to multidrug resistance were amplified by polymerase chain reaction (PCR)from Z23 and YD,and then cloned into plasmid pMD 19-T and sequenced.Results Y16B3 and Y16B8 gene fragments were amplified in the induced strain.Y16A11 gene fragments were amplified both in induced strain and in sensitive strain,but the homology of the two sequences was low.Conclusion The genomic differences exist between the induced multidrug resistant strain and sensitive strain of Shigella spp.