Abstract: OBJECTIVE To investigate the distribution of pathogens causing postoperative infections in children undergoing brain tumor resection and observe the impact on hemodynamics and expression of sPD-L1 so as to provide guidance for clinical treatment. METHODS A total of 69 children who underwent the brain tumor resection in the hospital from Jan 2012 to Dec 2014 were enrolled in the study; 38 children with postoperative infections were assigned as the infection group, and 31 patients without postoperative infections were assigned as the non-infection group; 40 healthy children who received the physical examination were set as the control group.The pathogens causing the infections were identified by using automatic microorganism identification system, and the hemodynamic parameters and change of expression of sPD-L1 were observed and compared among the three groups. RESULTS Totally 38 strains of pathogens were isolated from the children who had postoperative infections after the brain tumor resection, including 13 (34.21%) strains of gram-positive bacteria and 25 (65.79%) strains of gram-negative bacteria; the Staphylococcus aureus was the predominant species of the gram-positive bacteria; the Pseudomonas aeruginosa and Klebsiella pneumoniae were dominant among the gram-negative bacteria.The levels of CaO₂ and SjvO₂ of the infection group were significantly higher than those of the non-infection group and the control group(P＜0.05).As compared with the non-infection group and the control group, the levels of peripheral blood CRP and sPD-L1 were significantly elevated(P＜0.05).The Pearson correlation test analysis revealed that the CD4 and CD8 of the patients with infections were negatively correlated with sPD-L1, and the CRP was positively correlated with sPD-L1. CONCLUSION The children tend to have the infections after the brain tumor resection.The gram-positive bacteria and gram-negative bacteria are dominant among the pathogens.The postoperative infections may lead to the cerebral oxygen metabolic balance mechanism disorders and elevated levels of CRP and sPD-L1.