The purpose of this study is to investigate the differential expression of miRNA in pleural fluid and serum exosomes from patients with tuberculous pleurisy, which is to provide a basis for diagnosis and differential diagnosis of tuberculous pleurisy. Serum and pleural fluid specimens from 20 patients who had tuberculous pleurisy (experiment group) and 20 patients who had pneumonia with inflammatory pleural effusion (control group 2) were collected. 20 healthy persons’ serum (control group 1) were collected, too. The exosomes were separated and total RNA were extracted for expression level analysis of miRNA with real-time quantitative polymerase chain reaction (PCR) technology. The results showed that compared with control group 1, the level of miRNA expression in serum exosomes from control group 2 was increased in different degree, among them the let-7a-5p, let-7c-5p, let-7i-5p and miRNA-126-3p increased significantly. The expression level of miRNA in the serum exosomes from experimental group was higher than that of control group 2, especially let-7a-5p, let-7d-5p, let-7e-5p, miRNA-126-3p, let-7g-5p and let-7c-5p (P<0.05). Compared with control group 2, the expression levels of miRNA in pleural effusion exosomes from the experimental group were higher, and let-7f-5p, let-7g-5p, let-7d-3p were obviously higher than those in the control group 2. The expressions of miRNA in pleural effusion and serum exosomes were also significantly different in the experimental group. So it was concluded that the expressions of miRNA in pleural fluid and serum exosomes from patients with tuberculous pleurisy were different from general pneumonia with pleural effusion. The hsm-let-7 family members might be used as a good differential diagnostic index between tuberculous pleural effusion and common inflammatory pleural effusion.