Abstract: OBJECTIVE To observe the expression and significance of interleukin-6 (IL-6), interleukin-10 (IL-10),tumor necrosis factor (TNF-α), procalcitonin (PCT) and soluble triggering receptor-1 (sTREM-1) in patients with hospital acquired pneumonia, so as to provide the basis for early diagnosis and treatment of hospital acquired pneumonia. METHODS A total of 196 cases of patients with hospital acquired pneumonia from Jul. 2013 to Jun. 2016 were selected as HAP group, 195 healthy volunteers at the same period were selected as healthy group, survived patients within 28 d were included in HAP survival group, and dead patients within 28 d were included in HAP death group. Levels of IL-6, IL-10, TNF-α, PCT and sTREM-1 in the serum of HAP patients were measured on the 1st, 4th, 7th day of hospitalization, discharge and death dead. RESULTS HAP group of levels of sTREM-1, IL-6, IL-10, TNF-α, and PCT of HAP group were significantly higher than those in healthy group, and the indexes in HAP death group were higher than those in HAP survival group. During the treatment, the levels of sTREM-1, IL-6 and IL-10 in HAP survival group were significantly lower than those in HAP death group, and the difference was statistically significant (P<0.05). The levels of sTREM-1, IL-6 and IL-10 in HAP survival group decreased gradually with the time of treatment, and the differences were statistically significant between each other (P<0.05). The levels of TNF-α and PCT in HAP survival group were lower than those in HAP death group on the 1st, 4th, 7th day of hospitalization, discharge and death, and the differences were statistically significant. The levels of TNF-α and PCT in HAP survival group decreased gradually with the time of treatment, and there were significant differences between each other. CONCLUSION Expression levels of sTREM-1, IL-6, IL-10, TNF-α, and PCT expression in HAP patients were significantly higher than those in healthy people, The higher the level, the more severe the inflammatory response, and the worse of the treatment prognosis were obsewed.