Abstract: The strains of Yersinia enterocolitica (Ye) isolated from Fujian and Zhejiang provinces China were studied by serotyping, plasmid analysis, and restriction endonuclease analysis of plasmid (REAP). The results indicated that there were some differences not only in the strains of different serotypes, but also in the strains of same serotype. It was suggested that it maybe related with the different geographic sources of these strains.