Acute hepatitis E is found mainly in some developing countries in Asia and Africa. Generally, disseminated cases predominate in developed countries and epidemics in developing countries. Since 1980, there have been several epidemics in Xinjiang region of China, and there are reports of sporadic hepatitis E in other places, accounting for about 10% of the acute disseminated hepatitis, and at least six provinces, cities and autonomous regions have reported hepatitis E outbreaks and epidemics. Its epidemiological characteristics are similar to those of hepatitis A, transmitted by fecal-oral route. Water-based epidemics are the most common, and a small number of food-based outbreaks or daily life contact transmission. It has obvious seasonality, mostly seen in the rainy season or after flooding; the incidence of the population mainly young adults, pregnant women with high susceptibility, serious and high mortality rate; no family aggregation phenomenon. The incubation period is from 10 to 60 days, with an average of 40 days. Generally, the onset of disease is rapid and jaundice is common. Half of them have fever, accompanied by malaise, nausea, vomiting, pain in liver area. About 1/3 have arthralgia. Common cholestatic symptoms, such as itching of the skin, lightening of stool color is more obvious than hepatitis A. Most hepatomegaly, splenomegaly is less common. Most patients’ jaundice subsides in about 2 weeks, and the duration of the disease is 6-8 weeks, usually not developing into chronic. Pregnant women infected with HEV are seriously ill and prone to liver failure, especially the elderly, high mortality rate in late pregnancy, miscarriage and stillbirth can be seen, the cause may be related to low serum immunoglobulin levels.HBsAg positive people with overlapping infections of HEV, the condition is aggravated, and is prone to develop into acute severe hepatitis.