Abstract: Objective: To investigate the characteristics of pathogens and bacterial susceptibility in ventilator-associated pneumonia(VAP).Methods: The clinical characteristics of aetiological germ and bacterial susceptibility in 114 patients with VAP who were treated in our hospital from 2001 to 2002 were reviewed.Results: Gram-negative bacillus (GNB) accounted for 60.6%, Gram-positive coccus (GPC) 22.8%, fungi 15.7% and Gram-negative coccus (GNC) 0.8% among the cultivated aetiological bacteria.The main microorganisms were pseudomonas aeruginosa,staphylococcus aureus and Escherichia coli.Extended stectrum β lactamases accounted for 33.3% and methicillin resistant staphylococcus aureus 30.0%.Conclusions: The bacterum of VAP has high tolerance of drugs.More attention should be paid to the cultivateion of aetiological bcteria and selection of antibiotics in the treatment of VAP.