This study investigated the epidemiology of plague among marmots,Marmota himalayana,between 2007 to 2012 in Dege county in order to improve prevention and management plague.The main host species,marmots,were sampled monthly from May to October through a joint surveillance system covering the county,and pathogen cultures and serology tests were performed.Fleas as plague vectors were examined and identified.From 2007 to 2012,29 Yersinia pestis strains were isolated from marmots whose density was 0.12 individual/ha.The rate of detection of the bacteria was 0.4%for live marmots (n=540) and 28.7%for dead marmots (n=94) .For marmots (n=546) 0.92%showed positive serology,while 6.7%shepherds (n=283) were sero-positive.We captured 3107 fleas from 346 marmots,and the sampled fleas belonged to 7 species,7 genera and 3 families.The flea-infected rate and flea index was 62.12%,and 5.58%,respectively.The 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 prevent human plague epidemics.