摘要： In this paper,wild Pseudois nayaur and Procapra picticaudata were verified for the first time asthe intermediate hosts of Echinococcus granulosus in this part of the world-the Qinghai-Tibet Pla-teau.Using parasitic.pathological and immunlogical methods,data were obtaieed on the morphologyof hydatid cysts and the antigenicity of the cystic fluid.The role of Pseudois nayaur and Procaprapicticaudata in the epidemiology and epizootiology of hydatidosis and its natural nidus are discussed.