【Abstract】 Objective To understand  species composition, migration, distribution of the host animals in the historic epidemic areas of Dongyang, and to provide the primary data for the plague prevention and control. Methods The live trap was used in this investigation. The rats caught and the fleas collected from rats were identified, and the infection rate of rats and flea index were counted. Indirect hemorrhagic assay (IHA) was used to test the plague F1 antibody. Plague pathogen was cultured in vivo by four?step testing method. Results A total of 1269 rats were captured, belonging to 1 order 2 family 6 genus 10 species. Rattus norvegieus was the dominant species of indoor rested rats, accounted for 67.57%. While Eothenomys melanogaster Cashmere predominated in the wild with a proportion of 71.72%. And the rat density indoor and outdoor was 1.42% and 2.42%, respectively. There were only 10 rats that were found to be infected by flea among 1197 rats. And 17 fleas were collected. The infection rate of fleas to rats was 0.84%, and the total index of flea was 0.01. There were 1216 serology specimens sampled, which were all negative. No plague was isolated from 1007 specimens cultured in vivo. Conclusion R.norvegieus and E.melanogaster Cashmere were the dominant species indoors and outdoors,and and Ceratophyllus anisus was the main flea. Both the flea infections rate and total flea index were all lower than the control standard precaution line of plague. No positive results were observed. So far, there is no information showing the prevalence of plague during rats in Dongyang.