【Abstract】 Objective To know the species and distributions of carnivores and small mammals in Sanjiangyuan area. Methods The investigation was done by the night trap. Results There were many carnivores and small mammals in San jiang yuan, belonging to 4 orders, 11 Familys, 27 Genera and 51 species. Conclusion Marmota himalayana, Microtus oeconomus, Mus musculus, Cricetulus longicaudatus, Ochotona curzoniae, Felis catus, Canis familiaris, Vulpes vulpes, Vulpes corsac, Canis upus,Mustela eversmanni distributed widely  in Sanjiangyuan Area. Marmota himalayana was the main host of nature plague foci in the Qinghai-Tibet plateau.

【Abstract】 Objective To observe the toxicity of different insecticides to fleas and to screen out new and high effective insecticides. Methods The residual spraying was used in the field, and the bottle film method in the laboratory. Results The mortality rate of Xenopsylla cheopis was 100% after 24 h treatment with the concentration of 0.0025% for 10% Gongbaihai SC and 0.005% for 8% Dagongda WP. Jiapu insecticides could knock down the fleas within 0.5-3 min, followed by Gongbaihai and Dagongda within 5-7 min. The knocking time of Wanling produced by Dupont was the longest with the value of 10-20 min.  For death time, the fleas were all dead within 5 min after treatment, 30-40 min for Gongbaihai and Dagongda, and 1-1.5 h for Wanling of Dupont. Conclusion Dagongda and Gongbaihai can be used for the control of fleas in plague foci.

【Abstract】 This paper briefly discusses the biology and ecological characteristics of host animals and vectors infected naturally by Yersinia pestis district and the time and location of first isolation in Sanjiangyuan. It is to understand the species of animals and vectors infected and the function they plays in the plague epidemiology in order to provide the basis for the prevention and control of plague in Sanjiangyuan.