Abstract: OBJECTIVE To investigate the distribution and risk factors of secondary pulmonary infection in hospitalized patients with severe craniocerebral injury. METHODS The clinical data of 892 patients with pulmonary infection after severe craniocerebral injury treated in Harrison International Peace Hospital were collected as infection group. The distribution and drug resistance of pathogenic bacteria in sputum samples were analyzed retrospectively. At the same time, 120 patients with craniocerebral injury and no complications of pulmonary infection after craniotomy were selected as the uninfected group. The physiological indexes and related clinical indexes of the two groups were compared, and the risk of pulmonary infection was analyzed. RESULTS The pathogenic bacteria were 796 strains of gram-negative bacillus(89.2%), Klebsiella pneumoniae, Pseudomonas aeruginosa, and Bacillus baumann were the main pathogens; 84 gram-positive cocci(9.4%), Staphylococcus aureus and Streptococcus pneumoniae were the main pathogens; 12 fungi(1.4%). The rates of resistance to imipenem by Pseudomonas aeruginosa and Bacillus baumann were 37.1% and 60.2% respectively. Gram-positive cocci did not find strains resistant to vancomycin, tegacycycline and linazolamine. Univariate analysis showed pulmonary basic disease, use of more than three antibiotics, coma time >24 h, mechanical ventilation and smoking history were the risk factors of secondary pulmonary infection after craniocerebral injury. Multivariate analysis showed that coma time >24 h(OR=2.436, 95%CI:1.165-5.321, P=0.04) and mechanical ventilation(OR=2.720, 95%CI:1.343-6.986, P=0.02) were independent risk factors for pulmonary infection. CONCLUSION Gram-negative bacteria are the main pathogenic bacteria in postoperative pulmonary infection in hospitalized patients with severe craniocerebral injury. Drug resistance of pathogenic bacteria is not optimistic. There are many risk factors for secondary pulmonary infection in patients with craniocerebral injury.