There are many signs of improvement of severe pneumonia, such as reduction of lung symptoms and signs, control of systemic inflammatory reaction, absorption of lung lesions on chest X-ray, and others. 1. Reduction of pulmonary symptoms and signs: the patient’s cough, sputum, chest tightness and other symptoms improve. Severe pneumonia can cause dry and wet lung rales and rales, etc. As the condition improves, the patient’s lung signs will also improve. 2. Systemic inflammatory response is controlled: with the improvement of severe pneumonia, the patient’s blood test, C-reactive protein, calcitoninogen and other laboratory indexes are lower than before. 3. Resorption of lung lesions in chest radiographs: Generally speaking, when comparing the initial chest radiographs of the patients with the chest radiographs of the patients after the improvement of the treatment, it can be seen that the lung lesions of the patients have been absorbed obviously, which is an important sign of the improvement of the condition. 4. Others: the patient’s body temperature will drop, and the patient’s appetite and mental condition will also improve. Severe pneumonia needs to be actively diagnosed and treated to promote the recovery of the disease.