Objective : To study the differential expression and diagnostic value of miR-26a-5p and miR-151a-3p in plasma exosomes of tuberculosis. Methods : Differentially expressed miRNAs ( miR-26a-5p and miR-151a-3p) in tuberculosis exosomes were identified through bioinformatics website．Furthermore，70 tuberculosis patients (tuber- culosis group) and 58 healthy subjects ( healthy control group) were selected for clinical validation : Plasma exo- somes，extracted by differential centrifugation，were identified by Western blot，transmission electron microscopy， nanoparticle tracking analysis．The expression levels of miR-26a-5p and miR-151a-3p in plasma exosome were de- tected by RT-qPCR in the tuberculosis group and the control group．The diagnostic value of miR-26a-5p and miR- 151a-3p in tuberculosis was evaluated by ROC curve. Results : The characteristics of exosomes were identified by transmission electron microscopy，nanoparticle tracking analysis and Western blot，which showed that plasma exo- somes were extracted successfully．In clinical validation，the internal and external parameters were calibrated sim- ultaneously，the expression level of miR-26a-5p in plasma exosome of patients with tuberculosis was lower than that in control group (P＜0. 000 1) ，and the expression level of miR-151a-3p in plasma exosome of patients with tuber- culosis was higher than that in control group (P＜0. 000 1) ，which were consistent with the bioinformatics results. As a diagnostic marker，taking internal reference as the benchmark，the AUC of plasma exosome miR-26a-5p and miR-151a-3p for tuberculosis differentiation was 0. 872 and 0. 709，the AUC of the combined miR-26a-5p and miR- 151a-3p was 0. 915 (P ＜0. 000 1 ) ． Taking external reference as the benchmark ，the AUC of plasma exosomes miR-26a-5p and miR-151a-3p were 0. 829 and 0. 854 respectively ，the AUC of the combined miR-26a-5p and miR-151a-3p was 0. 911 (P＜0. 000 1) ． Conclusion The expression level of plasma exosome-derived miR-26a- 5p decreases in tuberculosis patients and the expression levelof miR-151a-3p increases，and the clinical diagnostic efficiency of bothis high，which may be a potential biomarker for the diagnosis of tuberculosis.