Abstract: An investigation on human parasites was conducted in 10 pilot sites in pasturage area of Qinghai, with 4 838 people under examination. A total infection rate of 32.1% was revealed. Of the 13 detected species of parasites, the respective infections were: Ascaris lumbricoides 12.8%, Trichuris trichiura 0.7%, Entamoeba histolytica 0.5%, Entamoeba coli 7.6% , Entamoeba hartmanni 0.3%, Endolimax nana 4.6%, Iodamoeba buetschlii 0.7%, Giardia lamblia 7.1%, Balantidium coli 0.02%, Blastocystis huminis 2.2%, Taenia saginata 1.2%, Enterobius vermicularis (below 12 years old) 15.5%,hydatid of Echinococcus sp. 3.0% . The results showed wild distribution and high prevalence of Ascaris and Enterobius infections, though less in infection rate and intensity than some other places due to the plateau climate. Hydatidosis, however, is the most hazardous parasitosis in Qinghai, so control practice is obliged to focus on this diseases.