Abstract: OBJECTIVE To investigate the distribution of pathogens causing nosocomial infections in patients of respiratory department and observe the influence on inflammatory reactions so as to provide guidance for clinical treatment. METHODS A total of 190 patients with nosocomial infections who were treated in the respiratory department from May 2012 to Sep 2014 were enrolled in the study, 90 respiratory department patients without infections were assigned as the non-infection group, and 90 healthy people who received the physical examination were chosen as the control group. The distribution of the pathogens causing the infections was observed, the levels of serum inflammatory factors were detected by means of enzyme-linked immunosorbent assay (ELISA) and were compared among the three groups of participants. RESULTS Totally 190 strains of pathogens were isolated from the 190 respiratory department patients with nosocomial infections, of which 106 (55.8%) were gram-positive bacteria, and 84 (44.2%) were gram-negative bacteria. The levels of serum inflammatory factors such as TNF-α, TGF-β, NFκ-B, MIP-2, SP-A, IL-1, and IL-2 were significantly elevated after the patients had infections, as compared with the control group and the non-infection group (P<0.01). CONCLUSION The gram-positive bacteria are dominant among the pathogens causing the nosocomial infections in the patients of respiratory department, and the patients with the infections have remarkable inflammatory reactions.