Objective To explore the prognostic factors of nosocomial infection in severe hepatitis and liver cirrhosis,and to assess its prevention and treatment.Methods A prospective study of nosocomial infection of severe hepatitis and liver cirrhosis was carried out in our hospital from Apr.1996 to Dec.2000.The prognostic factors of nosocomial infection in severe liver diseases was analyzed by logistic regression.Results The mortality of nosocomial infection in severe liver was 37 36%(34/91).Multiple regression analysis showed that prognosis was in order variables related to follow factors:Serum bilirubin,prothrombin time,complement C3,serum cholesterol,serum sodium,white blood cells count,polymorphonuclear cell rate,the kinds of nosocomial infection,severe complications and improper medical manipulations.The prognostic factors high correlated with nosocomial infection via analysis by logistic analysis were as follows:low serum complement C3 and low cholesterol.Conclusions The nosocomial infection were important factors that cause highly mortality in severe liver diseases.The prognositic factors high related with nosocomial infection of severe liver diseases were:low serum complement C3 and cholesterol level.