Objective To investigate the therapy and influencing factors for prognosis of ventilator-associated pneumonia(VAP) caused by multidrug-resistant organisms(MDROs).Methods 169 patients with VAP who were admitted to a hospital between January 2012 and December 2013 were included in analysis, 125 were in MDRO infection group and 44 in non-MDRO infection group.MDRO infection group was subdivided into MDR-A group(n=78, resistant to selected antimicrobial agents) and MDR-B group (n=47, sensitive to at least one kind of selected antimicrobial agent).Antimicrobial choice and prognosis between each group were analyzed and compared.Results 242 strains of pathogenic bacteria were isolated from airway secretion of VAP patients, 173(71.49％) were MDROs.The major pathogens causing VAP were Klebsiella spp.(n=66), Pseudomonas aeruginosa(n=64), Acinetobacter spp.(n=60), Staphylococcus aureus(n=27), and Escherichia coli (n=17), the percentages of MDROs of above pathogens were 68.18％, 50.00％, 91.67％, 88.89％, and 76.47％ respectively.The prognosis of MDRO infection group was poorer than that of non-MDRO infection group, MDR-A group had the worst prognosis(P<0.001).Persistent fever, leukocytosis, and progress of pulmonary inflammation in VAP patients suggested poor prognosis(all P<0.001);antimicrobial use in patients with effective therapy was higher than those in a worsened condition before onset, at the beginning of onset, and after culture of specimens(all P<0.001), while coma, early-onset VAP and multiple bacterial infection had no prognostic significance in patients with VAP(all P>0.05).Conclusion There is high incidence of MDRO infection in patients with VAP, effective antimicrobial therapy can improve the prognosis.