@#Abstract: Objective To explore the relationship between peripheral blood and pleural effusion tuberculosis (TB) infection effector T cells, and to further evaluate the value of combined pleural effusion adenosine deaminase (ADA) for rapid diagnosis of tuberculous pleurisy. Methods The test data of 80 cases of tuberculous pleurisy and 70 cases of nontuberculous pleurisy treated in the Sixth People's Hospital of Nantong City from January 2017 to December 2020 were analyzed. The TBinfected effector T cells were also detected simultaneously in the peripheral blood and the pleural effusion by the T-SPOT technique, and the pleural effusion ADA was detected by the rate method. The subject operating characteristic curve (ROC) was applied to take the optimal pleural effusion ADA threshold to compare the sensitivity and specificity of different critical values. Person phase analysis was applied to analyze the correlation between peripheral blood and pleural effusion T-SPOT.TB. Data of peripheral blood, pleural effusion T-SPOT.TB and ADA were integrated. Results When pleural effusion ADA>45 U/L, the sensitivity and specificity for the diagnosis of tuberculous pleurisy were 50.0% and 94.3%, respectively; when ADA > 25.15 U/ L, the sensitivity and specificity were 80.0% and 72.9%. When ADA > 45 U / L, pleural/ blood T-SPOT.TB spot ratio (spot forming cells, SFCs) > 2 times, the specificity for the diagnosis of tuberculous pleurisy was 100% (highest); when 25.15 U/L< pleural effusion ADA ≤ 45 U/L, pleural/blood T-SPOT.TB spot ratio > 2 times, the specificity for the diagnosis of tuberculous pleurisy was 92.3% (second). When pleural effusion ADA ≤ 25.15 U/L, and the pleural effusion/blood T-SPOT.TB spot number ratio > 2 times, with 83.3% specificity (the lowest of the three groups). Conclusions The level of pleural effusion ADA is one of the most used methods for diagnosing tuberculous pleurisy. Further combination of pleural effusion and blood T-SPOT.TB, if the ratio of pleural effusion / blood T-SPOT. TB spots is greater than 2 times, it can further improve the diagnosis rate of tuberculous pleurisy.