Abstract: OBJECTIVE To observe the clinical effect of tigecyline combined with meropenem on treatment of Acinetobacter baumannii intracranial infection.METHODS From Nov 2017 to Nov 2020, a total of 148 patients who had A.baumannii intracranial infection after neurosurgery were enrolled in the study and were divided into the tigecycline group and the combination group according to the treatment method, with 74 cases in each group. The tigecycline group was treated with intravenous injection of tigecycline, and the combination group was given ventricular injection of meropenem on basis of the treatment of the tigecycline group. Both groups were treated for 3 weeks. The levels of immune function indexes immunoglobulin A, G（Ig A, Ig G）, T lymphocytes（CD₃⁺, CD₄⁺, CD₄⁺/CD₈⁺）, oxidative stress indexes malondialdehyde（MDA）, total antioxidant capacity（TAC）, superoxide dismutase（SOD） and cerebrospinal fluid indexes（white blood cells, protein） were detected before the treatment and after the treatment for 1 and 3 weeks. The postoperative bedridden time, time of stable sign, postoperative length of hospital stay and therapeutic effects were statistically analyzed.RESULTS The levels of IgA, IgG, CD₃⁺, CD₄⁺, CD₄⁺/CD₈⁺, TAC and SOD of the two groups of patients were higher after the treatment for 1 and 3 weeks than before the treatment, while the levels of MDA,WBC and proteins were lower after the treatment for 1 and 3 weeks than before the treatment. The levels of IgA, IgG, CD₃⁺, CD₄⁺, CD₄⁺/CD₈⁺, TAC and SOD of the combination group were significantly higher than those of the tigecycline group after the treatment for 1 and 3 weeks, while the levels of MDA, WBC and proteins of the combination group were significantly lower than those of the tigecycline group（P＜0.05）. The total effective rate of the combination group was significantly higher than that of the tigecycline group after the treatment for 3 weeks; the positive bedridden time, time of stable signs and postoperative length of hospital stay were significantly shorter in the combination group than in the tigecycline group（P＜0.05）.CONCLUSION Tigecycline combined with meropenem may improve the immune function and oxidative stress response of the patients with A.baumannii intracranial infection, with the clinical effect remarkable.