Objective To investigate the seroprevalence of HEV infection and genotype. Methods ELISA were used for detecting anti-HEV IgG of the serum samples,the nested reverse transcriptase PCR ( RT-nPCR) was used for detecting HEV RNA in patient serum and swine bile samples. All samples were collected in 2005-2007 in some districts in Siehuan province. The primers used for genotyping were the ORF2 region of HEV genome. Results The anti-HEV lgG was detected positive in childrens 6.10% (41/672),adults 42.26% (280/661 ),swines 88.89 % (32/36),chickens negative (0/59). 1 case of 15 serum samples of anti- HEV IgM positive and 3 of 54 swine bile samples were positive for HEV RNA by RT-PCR. Sequenee analysis of 4 isolates has 92.1% to 98.6% nucleofide sequence homology.These isolates from human and swine were identified closely related to Ch-T21 strain 90.1%-96.9% sequence homology,which belonged to HEV genotype 4B. Conclusions The swine were the risk factors in the spread of hepatitis E virus.