Objective To study the changes of the population structure of 10-year-old rats in the plague surveillance areas in Hebei province, the causal relationship was monitored between the changes of the population structure and the epidemic of plague the population. Methods The 5-Meter-Clip was used. In the evening, the mousetrap was set up, and the mousetrap was collected on the second morning. The result was calculated. Results Through 10 years of monitoring, a total of 145 600 trappings were carried out and 1 257 rats were caught. The catch rate was 0.86%. There were 15 species collected, Cricetulus barabensis was the predominant species of small rats and accounted for about 77.17% of the species. Conclusion The population of small rats has changed in the plague surveillance area of Hebei province. This was resting phase in the natural foci of plague.