Abstract: Objective　To investigate the clinical application significance of Mycobacterium tuberculosis Tcell enzyme-linked immunospot tuberculous test（T-SPOT.TB test） in the diagnosis and differentiated diagnosis of tuberculous pleurisy.   Methods　A total of 124 participants were enrolled in this study，including 30 healthy controls，37 patients with tuberculous pleurisy，32 patients with malignant pleural effusion and 25 patients with non-tuberculous pleurisy. The Tcells to early secretary antigentic target6（ESAT-6） and/or culture filtrate protein 10（CFP-10） sensitive in peripheral blood mononuclear cell（PBMC） of participants were determined by T-SPOT.TB test. The results were compared with other related indicators [adenosine deaminase（ADA），tuberculosis antibody（TB-Ab） and smear]. Results　The positive rate of the tuberculous pleurisy group（91.9%） by T-SPOT.TB test was significantly higher than those of healthy control group（0.0%），malignant pleural effusion group（9.4%） and non-tuberculous pleurisy group（8.0%）. The differences were statistically significant（P＜0.05）. The sensitivity，specificity and diagnostic accuracy in the diagnosis of tuberculous pleurisy by T-SPOT.TB test were 91.9%，90.6% and 91.3%，which were superior to ADA and TB-Ab. Conclusions　T-SPOT.TB testis useful for the differentiated diagnosis of tuberculous pleural effusion. Ithas high sensitivity，specificity and diagnostic accuracy in the diagnosis of tuberculous pleurisy. Therefore，T-SPOT.TB testis worth in the clinical extention and application，and would be a supplementfor the diagnosis of tuberculous pleurisy.

Key words: Tcell enzyme-linked immunospot tuberculous test, Tuberculous pleurisy, Diagnosis