To identify Fallopia multiflora from its adulterants by comparing their matK sequences.Genomic DNA of different materials was extracted using modified cetytrimethyl ammonium bromide (CTAB) method. The double-strand matK genes were amplified using PCR method and then sequenced. The data were analyzed in Clustral W and MEGA 4.0 software package.Besides F. multiflora var. ciliinerve, the matK sequences of other adulterants show distinct differences with F. multiflora, whether for nucleotides substitutions or genetic distances; and the specific identifying sites for distinguishing F. multiflora and other Fallopia adulterants were found through further comparative analysis. Moreover, the 3 inspected materials were successfully authenticated by comparing the matK sequences.matK sequences can be used for the molecular identification between F. multiflora and its adulterant species.