Coughing with black sputum does not necessarily mean early stage lung cancer. The method used to determine early stage lung cancer is usually lung CT examination. There is no scientific basis for determining early stage lung cancer by observing whether there is sputum or whether there is coughing symptom. The cough with black sputum mentioned may be caused by other reasons, such as pneumonia or tuberculosis, which may produce coughing symptoms and black sputum if the condition is aggravated, so one should not judge whether a patient has early stage lung cancer by such clinical manifestations. When patients have similar conditions, they should go to the hospital for lung CT examination as soon as possible to exclude lung cancer to avoid delaying the condition and affecting the patient’s treatment.