Chronic bronchitis treatment and prevention: 1, quit smoking, prevent respiratory tract infection, inhalation of harmful gases; 2, antibiotics to control infection in acute attacks; use of drugs + oxygen therapy in the chronic phase; rehabilitation exercise therapy is recommended to increase the strength of respiratory muscles and abdominal muscles if possible. 3.Expectorant and cough suppressant – old and frail patients should avoid using strong cough suppressant drugs. 4. Influenza vaccination and pneumococcal vaccine can be applied. Bronchodilator drugs: 1, β2 agonists – salbutamol, terbutaline for short-acting, mainly for symptom relief, use as needed (minutes onset, 15-30min peak, maintenance 4-5 hours), salmeterol, formoterol for long-acting, can be maintained for 12h; 2, anticholinergic – ipratropium bromide by; better choice – tiotropium bromide. 3, Aminophylline-Oral, >5ug/ml has therapeutic effect, >15ug/ml starts to have side effects; suggest using long-acting theophylline drugs. 4.Hormone – long-term regular inhalation, currently considered very important for anti-inflammatory treatment of COPD.