Objective We detected the changes of peripheral blood serum procalcitonin (PCT), IL-17 and sTREM-1 levels in patients receiving mechanical ventilation and being to be ventilator associated pneumonia (VAP), to explore the early diagnostic value of PCT, IL-17 and sTREM-1 levels in patients with VAP. Methods During April 2015 to April 2016, we collected 61 patients receiving mechanical ventilation and being to be VAP as the research individuals in ICU of our hospital. According to the peripheral blood collection time, the researchers were divided into 3 groups: the cases without mechanical ventilation as the mechanical ventilation 0 h group (MV 0 h); the cases with mechanical ventilation for 48 hours and not occurred VAP, as the mechanical ventilation 48 h group (MV 48 h); once diagnosed, the cases were included into VAP group. PCT, IL-17 and sTREM-1 levels of each group were detected by ELISA method, and the data were statistically analyzed using SPSS 18.0 statistical software.  Results The serum levels of PCT, IL-17 and sTREM-1 in the group of MV 48 h were higher than those in the group of MV 0 h, but without statistical significance (P>0.05). The serum levels of PCT, IL-17 and sTREM-1 of VAP group were significantly higher than those in the group of MV 0 h, MV 48 h (P＜0.05). The area under the ROC curve of PCT was 0.856. When the serum PCT level reached 104.7864 pg/mL, the sensitivity of the early diagnosis of VAP was 73.9%, and the specificity was 84.4%. The area under the ROC curve of IL-17 was 0.877. When the serum IL-17 level reached 136.9726 pg/mL, the sensitivity of the early diagnosis of VAP was 70.8%, and the specificity was 91.7%. The area under the ROC curve of sTREM-1 was 0.813. When the serum sTREM-1 level reached 95.4204 pg/mL, the sensitivity of the early diagnosis of VAP was 72.4%, and the specificity was 79.3%.  Conclusion The peripheral blood serum PCT, IL-17 and sTREM-1 of in patients with VAP all have a certain diagnostic value.