Objective To investigate the effect of bronchofibroscopic bronchoalveolar lavage on serum inflammatory cytokines in the patients with severe ventilator-associated pneumonia(VAP) .Methods 68 cases of severe VAP were divided into the control group and observation group according to the random number table method ,34 cases in each group .The control group used conventional alveolar lavage plus sputum suction treatment ,while the observation group adopted bronchofibroscopic bronchoalveolar lavage plus sputum suction treatment .The lung infection control time ,mechanical ventilation treatment time ,time of body temperature recovery to normal ,pulmonary infection score(CPIS) ,white blood cell(WBC) count ,respiratory function ,blood gas indexes and serum inflammatory factors levels were compared between the two groups .Results The lung infection control time ,mechanical ventilation treatment time ,recovery time of normal temperature ,blood gas indexes and serum inflammatory factors levels after treatment in the observation group were significantly superior to those in the control group (P＜0 .05) .Conclusion Bronchofibroscopic bronchoalveolar lavage can significantly improve the respiratory function and blood gas indexes ,reduces the serum inflammatory factors levels in the patients with severe VAP .