Mild to moderate pneumonia is usually treated with anti-infective therapy for 5-7 days, while severe cases and other special circumstances require a longer course of treatment. Pneumonia is mainly caused by various pathogenic microorganisms, with bacterial pneumonia being the most common. Once the diagnosis of pneumonia is confirmed, antibiotics should be used as soon as possible, and generally can be discontinued after the temperature has dropped for 2~3 days and respiratory symptoms have improved significantly. However, the exact course of treatment depends on the patient’s condition and symptoms. For common bacterial infections such as Streptococcus pneumoniae, if the symptoms are mild, the course of anti-infective treatment is about 5-7 days, which should be adjusted according to the situation. Atypical pathogens such as Mycoplasma and Chlamydia pneumonia, anti-infective time needs to be extended, about 10-14 days. Special bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa, which are prone to necrosis of lung tissue, need to be extended to 14~21 days. Pneumonia anti-infection specific time needs to be based on the condition, the type of infectious agent, symptomatic relief, etc. It is recommended to listen to the guidance and advice of professional doctors.