Abstract: Objective To determinate the feature of pleural effusions by several detective medthods.Methods Several detective Methods were used to determinate the features of 89 cases of pleural effusions.Results The Results show that the differential value of pleural biopsy is significantly higher than other detective methods.The diagnostic value of the tubercle bacillus DNA polymerase chain reaction (TB DNA PCR) is better in pulmonary tuberculosis,and the diagnostic value is better by detecting peripheral blood than by detecting pleural effusions (P＜0.01)。Conclusion The features of pleural effusions can be differentiated more effectively and exactly by combining the pleural biopsy and TB DNA PCR.

Key words: Pleural effusions, Polymerase chain reaction