Objective To investigate the effect of ulinastatin in adjuvant treatment of ventilator-associated pneumonia(VAP)and preliminary clinical efficacy of the therapy mechanism.Methods 76 patients with ventilator-associated pneumonia from January 2015 to February 2016 in Qingyuan People's Hospital of Zhejiang Province were selected and randomly divided into control group and observation group,38 cases in each group.Two groups were given mechanical ventilation,phlegm,anti infection,rehydration,nutritional support and other conventional treatment,the observation group on the basis of routine treatment for ulinastatin adjuvant therapy,comparison of two groups of treatment,the simultaneous determination of serum interleukin-6(IL-6),C-reactive protein(CRP)and procalcitonin(PCT)and tumor necrosis factor alpha(TNF-alpha)levels were measured before and after treatment.Results The total efficiency of the observation group was 94.74％,significantly higher than the control group 78.95％,the difference was statistically significant(P<0.05),the two groups after treatment of serum CRP and PCT levels were decreased significantly compared with before treatment,the observation group after treatment,serum CRP and PCT levels were(45.19+5.79)mg/L and(1.08+0.36)μg/L was significantly lower than that before treatment and control group after treatment,the difference was statistically significant(P<0.05),the two groups after treatment of serum IL-6 and TNF-α levels were decreased significantly compared with before treatment,the observation group after treatment,serum IL-6 and TNF-α levels were(165.29+19.23)pm/mL and(1.16+0.25)pm/mL,was significantly lower than that before treatment and control group after treatment,the difference was statistically significant(P<0.05).Conclusion The inflammatory reaction in patients with ventilator-associated pneumonia ulinastatin can effectively reduce auxiliary patients,reduce inflammatory factors on lung injury,can alleviate the disease progression and to improve its prognosis.