Yellow sputum is in most cases caused by bacterial infection, so antibiotics are required. When a patient has yellow sputum, further improvement of blood routine, C-reactive protein, calcitoninogen, sputum culture and other related tests are needed. If the patient has elevated white blood cells, neutrophils, neutrophil percentage, as well as C-reactive protein and calcitoninogen, the diagnosis of bacterial infection is clear. Mild cases can be treated with oral amoxicillin, cefixime, azithromycin, and levofloxacin, while severe cases can be treated with anti-infective therapy by sedative cefoperazone sodium sulbactam, cefodizime, and cefuroxime. Antibiotics can also be selected according to the drug sensitivity results. Patients with yellow sputum who have sticky sputum that cannot be easily coughed up can use expectorant drugs, such as aminoglutethimide, eucalyptus citrulline, acetylcysteine, bromhexine, etc.