Tuberculosis test is the most specific method to confirm the diagnosis of pulmonary tuberculosis, and finding tubercle bacilli in sputum is the main basis to confirm the diagnosis of pulmonary tuberculosis. Smear antacid staining microscopy is fast and easy in China atypical mycobacteria are still rare, so antacid mycobacteria-like should be, the diagnosis of pulmonary tuberculosis can be basically established. Direct thick smear positive rate is better than thin smear, and is commonly used. Fluorescence microscopy is suitable for rapid examination of a large number of specimens. Without sputum or children will not cough, early morning gastric lavage can be used to find TB bacilli, admittedly also through fibrinoscopy into the poor, or from its shabu juice to find TB bacilli. Positive sputum bacilli indicates that their lesions are open and the opinion is infectious. If the amount of excreted bacilli is high (more than 100,000 per ml), direct smear is easy to be positive, for social infectious source in sputum bacilli is less (less than 10,000 per ml), the collection method is available. Culture method is more accurate, in addition to understanding the ability of the tuberculosis bacilli to grow and reproduce, and can be used for drug sensitivity testing and mycotype identification. The growth of M. tuberculosis is slow and usually takes 4-8 weeks to be reported using modified Roche medium. Culture is time-consuming, but accurate, reliable and specific. It is especially important if the smear is negative or if the diagnosis is in doubt. The specimen will be amplified in vitro by polymerase chain reaction (PCR) method, so that the microscopic TB DNA contained, detected by electrophoresis, 1 TB bacterium contains about 1fg DNA, 40 TB bacterium can have a positive result. The method does not require in vitro pre-culture, specificity, 2 days to report, fast, simple, and can identify the type of bacteria, the shortcoming is that there may be false positive or false negative.