Objective To discuss the relevant factors causing hospital infection of lung in surgical department of nurye of nurve in ICU patients after tracheotomy.Methods Using prospective and retrospective studies to analyze during 2004-2007 sputum bacteria cultures,drug sensitive tests and relative clinical data of 184 cranial injury patients.Results Incidence rate of hospital infection of lung was 89% in this group.Most occurred (3.60 -0.64) days after tracheetomy.The death rate of infected patients was significantly higher than non- infected patients(P < 0.05).Three hundred and seventy- five strains of parhngenic bacteria were found of them two hundred and ten granmegative, eighty-six gram-spostive, seventy-nine fungi, seventy-nine fungi all mix infection with bacteria.Conclusion Hospital infection of lung in cranial injury patients after tracheotomy is not relate to use of dexamethasone,H2 receptor antagonist and acid pump inhibitor,but is related to seriousness of cranial injury,environmental pollution of the hospital and infection causing by gram-negative bacteria.Prevention and control should be done within the first week after tracheotomy with active treatment of original disease and use of ICU.Also effective are controlling the environmental pollution of the hospital and selection of antibiotics based on antimicrobial susceptibiliy testing to control nosocomial.