Abstract: ObjectiveTo investigate epidemic feature and prevalent trend of plague among host animals from 2007 to 2012 in Dege county for prevention and treatment of plague.MethodsThe hosts were sampled through a joint surveillance system covering the county,and pathogen culture and serology test were also performed.Moreover,the vector insects were determined.ResultsFrom 2007 to 2012,29 Y.Pestis strains were isolated from marmots,with a density of 0.12 individual/ha.The detection rate of the bacteria was 0.37%for live marmots and 28.72%for dead marmots.Serum positive rate of marmots was 0.92%and that of the shepherd was 6.71%.We captured 3 107 fleas from 346 marmots,and the sampled fleas belonged to 7 species,7 genera and 3 families.The infected rate of the flea was 62.12%,and the flea index was 5.58.ConclusionThe animal plague in Dege county was prevalent from 2007 to 2012,and more attention should be taken to monitor plague epidemiology among the hosts in order to prevnt human plague epidemic.