In clinical work, it is found that many patients only pay attention to how doctors use drugs after consultation and ignore the laboratory examination of sputum before and during treatment, which is very wrong, and even some doctors fail to pay attention to it and do not supervise it in time. The importance of sputum TB examination is as follows: 1. It is the basis for correct diagnosis. The most important gold standard of TB diagnosis is to find TB bacilli in sputum. Diagnosis of TB disease based on symptoms and chest X-ray including CT alone is not completely correct and there is a possibility of misdiagnosis. 2. It is the best indicator to judge the effect of treatment. Some patients and doctors only analyze the change of disease according to the patient’s description of the symptoms; or judge the disease according to the change of chest film and CT film, which is one-sided and unscientific. The criteria for judging the good or bad condition and drug discontinuation must be based on the results of sputum TB examination. 3, sputum culture and drug sensitivity test is the fundamental basis for the development of a reasonable drug regimen. 4, pay attention to the method of sputum retention and the quality of sputum is very critical.