If patients with pneumonia have sputum excretion they must do sputum culture, unless they are those who do not have any sputum at all, because they do not have it and cannot stay hard, and the retained specimens are not qualified and the results are not meaningful. For patients who do not have any sputum at all, you can try to do sputum induction and retention. Why should we keep sputum culture? Because once the diagnosis of pneumonia is confirmed, the physician will consider the possible pathogens of infection based on the patient’s signs and symptoms and the presence of underlying disease, and immediately give the patient antibacterial medication based on experience. If the patient’s symptoms tend to improve after empirical antibacterial medication, this is the best outcome. If the patient is infected with drug-resistant bacteria or specific pathogens, it is necessary to select sensitive antibiotics based on sputum culture and drug sensitivity testing. Meaningful pathogenic findings can guide the clinic and provide timely and effective symptomatic treatment to relieve the patient’s symptoms, because improper treatment can result in serious complications, so sputum culture must be retained for patients with pneumonia.