Local inhabitants in 8 towns/townships of the counties Yushu, Zhiduo and Chengduo were examined with serology and ultrasound in 2006. Among 2 251 people tested by indirect hemagglutination (IHA), 207 showed anti-hydatid IgG positive (9.2%). Ultrasound examination found 106 cases out of 2581 people, with a morbidity of 4.1%. Females showed higher sero-positive rate (11.3%) and morbidity rate (5.0%) than males (6.6% and 3.0% respectively). The highest sero-positive rate was in the group of 40-49 years old (16.4%). The morbidity rate increased with age, with the highest rate (15.5%) in the group of 60 years old and above. Occupationally, those involved in semi-agriculture and semi-animal husbandry showed highest sero-positive rate and morbidity rate, 21.5% and 11.4% respectively. The survey demonstrated that the prevalence of hydatid disease in human population is at a high level in Yushu Tibetan Autonomous Prefecture.