Abstract: OBJECTIVE To explore the infections of patients after orthopedic surgery and detect the changes of the levels of interleukin-6 (IL-6), interleukin-8 (IL-8) and T lymphocyte subsets, so as to provide references for clinical control and treatment of postoperative infections of orthopedic. METHODS A total of 65 patients who underwent orthopedic surgery from Dec. 2014 to Oct. 2016 were selected as the study subjects. The incidence of postoperative infections was statistically analyzed. Totally 21 cases of postoperative infections were set as infection group, and 44 cases without infections after operation were set as control group. The pathogens of the infected patients were cultured and identified. The changes of IL-6, IL-8 and T lymphocyte subsets were observed. RESULTS Totally 21 cases were infected in the 65 cases of orthopedic surgery, and the infection rate was 32.31%. Totally 84 strains of pathogenic bacteria were detected, among them, 51 strains were gram-negative bacteria, accounting for 60.71%, 29 strains were gram-positive bacteria, accounting for 34.53%, and 4 strains were fungi, accounting for 4.76%. The levels of IL-6 and IL-8 of infection group were (42.16±3.52)ng/L and (54.15±7.91)ng / L, which were significantly higher than (14.81±7.35 )ng / L and (42.18± 10.17)ng / L of non-infected group. The levels of CD₃⁺, CD₄⁺ and CD₄⁺/CD₈⁺ of infection group were (58.29±6.04)%, (43.94±2.75)% and (0.64 ± 0.03)%, which were significantly higher than (49.01 ± 5.72)%, (22.59±3.27)% and (1.08±0.31)% of non-infected patients. CONCLUSION Infection in orthopedic patients is serious, and the main pathogens were gram-negative bacteria. Among them, IL-6, IL-8 and T lymphocyte subsets are higher in infected patients than in non-infected ones. These indexes can be used as the important indicators of clinical postoperative infections.