The symptom of lung cancer with more sputum alone cannot evaluate the severity of lung cancer, and it should be combined with other examination results. Lung cancer with much sputum may be the stimulation of lung tissue by tumor cells, which makes the patient make the secretion of patient’s respiratory tract increase, at this time, active anti-tumor treatment is needed to reduce the stimulation of lesions on lungs as well as the compression of airways. Patients with lung cancer may cause patients to cough and cough up sputum with more sputum if they are also combined with infections, such as viral infection, bacterial infection, chlamydia or mycoplasma infection, and so on. However, the severity of lung cancer is not judged by this symptom, but mainly by CT and other examinations to determine the size of the lesion and whether it is accompanied by lymph nodes and distant metastasis to judge the severity of lung cancer. It is recommended that patients should consult the doctor in time if they have persistent discomfort, and make clear diagnosis and active treatment after completing relevant examinations, so as to avoid delaying the condition.