Abstract: ObjectiveTo investigate the influencing factors of nosocomial infection among elderly patients in intensive care unit(ICU)and to supply scientific evidences for intervention measures to reduce incidence of nosocomial infection in ICU.MethodsWith cluster sampling method,439 elderly patients with nosocomial infections and 713 elderly patients without nosocomial infections in ICU in a provincial hospital of Shandong province from 2004 to 2010 were investigated.Results There were significant differences in gender,age,disease grading,the number of underlying diseases,hospitalization time,immunosuppressant,vascular catheter,urinary catheter,ventilator,tracheal intubations,tracheotomy,previous diabetes, original hypertension,previous pulmonary infection,pressure ulcers,respiratory disease,cerebrovascular disease,multiple injuries,and the occurrence of shock between infection group and non-infection group(P<0.05 for all).The results of multivariate analysis showed that hospitalization time,the number of underlying diseases,vascular catheter,tracheal intubations, tracheotomy,and previous pulmonary infection were risk factors of nosocomial infection among the elderly patients.ConclusionHospitalization time,the number of underlying diseases,vascular catheter,tracheal intubations,tracheotomy,and previous pulmonary infection were influencing factors of nosocomial infection among elderly patients in ICU.Relevant control measures should be taken for the influencing factors to reduce the incidence of nosocomial infection.