Abstract: This paper presents the result of epidemiological survey of Clonorchis sinensis infection in Hunan during 1971-1990. The data collected from 9 out of 20 endemic counties/cities were under study. An overall infection rate of 7.5% (ranged from 2.1% to 85.2%) was showed in 40 509 people experienced stool examination. Age related analysis indicated significant higher infection rate of 19.8% in elder group 15 years old than that of 3.5% in children 15 years old (χ 2=114.2525, P 0.01). The infection rate in males (12.9%) was significantly higher than that in females (8.8%). Parafossarulus striatulus was the major first intermediate host, while Pseudorasbora parva and Rhodeus sinensis being the main second intermediate host. An investigation on the second intermediate host in 8 counties revealed a mean infection rate as high as 54.4% in P. parva. People got the infection mostly through taking fish baked by fire, whereas raw and half done fish was also consumed in some localities. Clinical manifestations of infected persons included dyspepsia, diarrhea, and hepatomegaly. Dog and rat were found to be important reservoirs in some counties.