Tuberculosis is a chronic infectious disease of the lungs caused by the invasion of Mycobacterium tuberculosis into the body under certain conditions, of which those with sputum excretion are infectious tuberculosis. How to determine the activity of pulmonary tuberculosis? Progression of lesion 1, with systemic toxicity or local respiratory symptoms such as low fever, night sweats, cough and sputum. 2.Sputum bacteria, especially positive sputum culture, or change from negative to positive. 3.X-ray manifestation: showing exudative, caseous, proliferative lesions or finding newly emerged infiltrative or disseminated lesions, or the original lesion is enlarged in scope than before, and fresh cavity appears or the original cavity is enlarged than before. 4, CT shows central nodular shadow of lobules, or vernal bud-like changes with blurred margins. Stable lesion 1.No longer have relevant clinical symptoms. 2, sputum bacteria more than 6 consecutive negative (2 times per month), if there is a cavity need continuous observation for 1 year. 3.X-ray shows fibrous hard nodules or calcified lesions with cavity closure. The unclosed cavity is fibrous thick-walled and sputum negative for 1 year continuously, that is “purified cavity”. 4.CT examination: mediastinal window shows high density spots and fiber strip shadows, and the lesion scope and morphology are not much different compared with the lung window. It suggests that the majority of the lesions are fibrous sclerotic or calcified lesions. 5.Patients with stable lesions continue to be observed for 2 years, still no active performance, can be considered clinically cured.