Abstract: The study was aimed to establish an indirect ELISA for epidemiological investigation of hepatitis E virus（HEV） infections in pigs from the major pig-producing regions of Zhejiang Province. The gene fragment covering immunogenic epitopes of HEV ORF2 was synthesized and expressed in Escherichia coli. Western blot analysis revealed that the purified protein reacted to HEV positive sera, but not to positive sera of other common viruses infecting pigs. An indirect ELISA system was then developed using truncated HEV ORF2 protein as the coating antigen and had diagnostic accuracy of 915 % as compared with a diagnostic kit for HEV antibodies. A total of 1 330 serum samples were collected from 46 pig farms in Zhejiang province during 2005-2008 and tested for seroprevalence of HEV using the indirect ELISA. The average HEVpositive rate was 557% (741/1 330). The positive rate of 2005 and 2006 was 627% (175/279) and 614% (301/490) respectively, much higher than those of 2007 (431%, 59/137) and 2008 (486%, 206/424). Meanwhile, the pigs aged 66-100 days had a statistically higher positive rate (582%, 110/189）as compared with that of pigs of 30-65 (397%, 73/184） and 101-160 (441%, 83/188) days. Only three herds in the study were HEV antibodynegative, indicating high seroprevalence of HEV in the pig populations in Zhejiang Province.