Objective To investigate the status of rodent, livestock, and poultry carrying Yersinia enterocolitica in plague foci maintained by Citellus dauricus in Ar Horqin Banner, Chifeng, Inner Mongolia, China, and to provide scientific evidence for prevention and control of the disease and study of the plague focus. Methods Villages in the C. dauricus plague foci were chosen as the sampling centers, and the farmland and grassland in outward concentric circles were sequentially included in the sampling area. Feces, tongue roots, throat swabs, and intestinal contents of rodent, livestock, and poultry were separately collected, and different Y. enterocolitica strains were isolated, cultured, identified, and serotyped. PCR analysis was conducted to detect the toxicity genes of Y. enterocolitica. Statistical analysis was performed by chi-square test. Results A total of 3837 samples were collected from 2009 to 2012. Seventeen Y. enterocolitica strains were isolated and the overall detection rate was 0.44%. Of the 16 strains detected in 2011, 13 were from pig feces and 3 from rodent intestines. The pathogenic strain of serotype O:3 and biological type Ⅲ carrying toxicity genes ail, ystA, and rfbC was isolated from pig feces. Conclusion Pigs and rodents in Shaogen, Ar Horqin Banner, carry Y. enterocolitica. Pigs are the major carrier of pathogenic Y. enterocolitica. Further investigation of the distribution pattern of Y. enterocolitica between human and animal hosts in the area is necessary.