目的：为了探讨聚合酶链反应（ＰＣＲ）ＤＮＡ扩增对诊断活动性肺结核的临床价值。方法：采用ＰＣＲ扩增技术对６９例活动性肺结核病人的痰（３５例）和胸水（３４例）进行检测。结果：痰灵敏度６５７１％（２３／３５），特异度７３９１％（１７／２３），准确度６８９６％（４０／５８），胸水灵敏度６１７６％（２１／３４），特异度８５７１％（６／７），准确度６５８５％（２７／４１）。并同涂片和培养法比较，时间上有益于结核病的早期诊断，但前者比后两者敏感性高，特异性差。结论：用ＰＣＲＴＢ－ＤＮＡ扩增作为临床诊断活动性肺结核的常规手段，尚需进一步探讨 Objective: To investigate the clinical value of polymerase chain reaction (PCR) amplification in diagnosis of active pulmonary tuberculosis. Methods: The sputum (35 cases) and hydrothorax (34 cases) in 69 patients with active pulmonary tuberculosis were detected by PCR amplification. Results: The sputum sensitivity was 65.71% (23/35), the specificity was 7391% (17/23), the accuracy was 6896% (40/58), the sensitivity of pleural effusion was 6176% (21/34) The specificity was 8571% (6/7) and the accuracy was 6585% (27/41). Compared with the smear and culture method, it is beneficial to the early diagnosis of tuberculosis in time, but the former is more sensitive and poor specific than the latter two. Conclusion: PCRTB-DNA amplification as a routine diagnostic tool for active tuberculosis needs further exploration