Abstract: 【Abstract】 This study was performed to determine the prevalence of hydatid disease in Baiyin District, Pingchuan District, Jingyuan County, and Jingtai County of Baiyin City in Gansu Province during June-December, 2011. Echino-coccus infection in human was investigated by serological assay and type-B ultrasound examination. Sheep and dogs were dissected for pathological examination and their fecal samples were determined by ELISA. The prevalence of hydatid disease in human was 0.29%（52/17 699）. There was significant difference among different education levels, different districts, and age groups（P<0.05）. The sero-positive rate in children was 2.98%（198/7 376）. The infection rate in sheep was 2.83%（142/5 026）. The fecal antigen positive rate in dogs was 3.84%（73/1 902）.

Key words: Hydatid disease, Baiyin, Prevalence, Animal host