Abstract: Hepatitis E virus (HEV) is one kind of RNA virus, which mainly causes one kind of acute infectious hepatitis–hepatitis E. Hepatitis E is transmitted in a faecal-oral route, and usually is caused by contaminated drinking water. Hepatitis E occurs predominantly in developing countries, in Asia, Africa and America. Hepatitis E accounts for more than 50% of acute viral hepatitis in some areas, and is important agent which causes illness and to die. Our country is HE highly prevalent area; the disease incidence rate presents the fast growth. Human is prone to infect HEV, which cause the miscarriage or the death in pregnant woman, and mortality rate reaches 20%~30%. The infection crowd primarily is the great age child and the young adults, while the baby is rare. HEV may infect not only the human, but also is widespread in the animal. This article has carried on the summary of it from the etiology, the epidemiology, the examination method and its vaccine development several aspects.