If yellow sputum is still present after pneumonia treatment, it is generally considered that there is still bacterial infection in the respiratory system. It is necessary to rule out the existence of drug-resistant bacterial infections, drugs not covering the causative organisms, or insufficient anti-infective treatment, and anti-infective treatment is still needed. 1. Drug-resistant bacterial infection: such as Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, multi-drug-resistant bacteria and other infections, there may still be yellow sputum after the treatment of pneumonia, and it is necessary to carry out repeated sputum cultures to identify the causative organisms and to choose the sensitive antimicrobial drugs according to the results of the drug sensitization. 2. Drugs do not cover the causative organisms: special pathogens such as Mycoplasma, Chlamydia, Legionella, Pseudomonas aeruginosa, Aureobacteria and other infections, the use of general drugs may not cover the causative organisms, and there is still yellow sputum after anti-inflammatory treatment, and it is necessary to replace the broad-spectrum anti-bacterial drugs to carry out anti-infective treatment. 3. Insufficient anti-infective treatment: after Mycoplasma, Pseudomonas aeruginosa, Klebsiella pneumoniae, Aureobasidium, sepsis caused by Escherichia coli and other special pathogens, the anti-infective treatment course needs more than 21 days, and fungal infections even need to be treated for 3 months, and insufficient treatment can lead to recurrence of yellow sputum. In conclusion, yellow sputum after pneumonia treatment, timely medical treatment to improve the relevant examination, such as blood routine, biochemical routine, chest CT and other tests, a clear diagnosis, the cause of the treatment.