ObjectiveTo investigate the clinical characteristics and risk factors for healthcareassociated infection(HAI) in patients with severe chronic hepatitis B(CHB), and provide  theoretical basis for preventing and controlling HAI.MethodsRetrospective survey was used to investigate the occurrence of HAI in hospitalized patients with severe CHB in a hospital between January 2012 and  January 2015,  risk factors for HAI were analyzed.ResultsA total of 126 patients with severe CHB were investigated,49 patients developed 106 times of HAI, incidence of HAI was 38.89%. The main HAI site was respiratory tract （n=47，44.34%），the next was  abdominal cavity (n=34, 32.08%).  A total of 76 isolates of pathogens were detected, gramnegative bacteria,  grampositive bacteria, and fungi accounted for 53.95%（n=41），43.42%（n=33），and 2.63%（n=2）respectively. Risk factors for HAI in patients with severe  CHB  were patients’ age≥60 years, length of  hospital stay≥30 days, complications, invasive operation,  serum albumin＜35 g/L, and white blood cell count(WBC)<4×109/L.ConclusionIncidence of HAI in patients with severe CHB is high, the majority are respiratory tract and abdominal cavity infection, risk factors are old age, long length of  hospital stay, invasive operation, hypoalbuminemia, and low WBC count.