Objective To analyze the outcome of the epidemiological investigation on an animal plague in Dingbian County of Shaanxi Province.Methods The region of 25 square kiolmeters(km2)in Hongliugou Town was selected as monitoring point of plague to investigate on host animals,etiology and serology.The epidemic area was classified,deratization and depulization were correspondingly adopted.Health education was carried out for prevention knowledge of plague,and questionnaire survey was conducted among residents and medical staff in the epidemic area.Result The average rat density in monitoring site was 8.38 rats per hectare in Hongliugou Town.Average rate infected with flea and flea index were 50.4%(56/111)and 1.81,respectively.The epidemic area was classified 3 types,and came up to the demand after corresponding measures adopted.In the epidemic area,the pass rate of the prevention and control knowledge were 62.00%(31/50)in residents and 92.98%(53/57) in medical staff.Conclusions Plague epizootic can be discovered by exercising regular monitoring and controlledimmed iately and effectively by taking the appropriate control measures.