Objective:To reveal the significance of microRNA 155 (miR-155) level or the suppressor of cytokine signaling 6 (SOCS6) level in distinguishing the differentiating tuberculosis (TB) infection.Methods:A case-control study was conducted. A total of 60 patients were enrolled in the study retrospectively, including 20 patients with active pulmonary tuberculosis, 20 patients with latent tuberculosis and 20 patients with other pulmonary infectious diseases (non-TB infection), who visited The Third Affiliated Hospital of Third Military Medical University from January to June of 2017. The expression level of miR-155 and SOCS6 in peripheral blood mononuclear cells (PBMC) of from these patients were examined by using the quantitative real-time polymerase chain reaction (qPCR) methods. The associated statistics and graphs was utilized to obtain the relationship, which were reflected by the Co-index receiver operating characteristic(ROC) curve or calculating the area under ROC curve (AUC), between the miR-155 and SOCS6 in differentiating tuberculosis infection by using the Logistic Regressive analysis methods, MedCalc and GraphPad Prism 8.0 software.Results:Neither of the three index miR-155 (AUC=0.663, P=0.031), SOCS6 (AUC=0.708, P=0.002) and Co-index (AUC=0.718, P=0.001) was outstanding to distinguish the tuberculosis infection and non-TB infection. Moreover, the miR-155 (AUC=0.867, P<0.001) and Co-index (AUC=0.875, P<0.001) were similar sufficient ( Z=0.142, P=0.887) to distinguish the active and latent infections. The Co-index (AUC=0.923, P<0.001) was better ( Z=2.586, P=0.010) than SOCS6 (AUC=0.723, P=0.007), and similar ( Z=1.585, P=0.113) to miR-155 (AUC=0.835, P<0.001) on the distinguishing active and non-TB infection. Conclusions:By performing the qPCR and the correlation-analysis, miR-155 has been considered as a potential biomarker for differentiating latent tuberculosis infection from active tuberculosis infection. Conjoint analysis of miR-155 and SOCS6 benefits the distinguishing active TB infection from other pulmonary infectious diseases.