The narrowed airway, remodeling, and emphysema in chronic obstructive pulmonary disease (COPD) are caused by chronic inflammation in the peripheral lung tissue. The inflammation in COPD is characterized by increased numbers of macrophages, neutrophils, and T lymphocytes (mainly CD8 lymphocytes). The immune response in COPD include both innate immunity and acquired immunity, with the expression of many intermediate chemicals derived from inflammatory cells and structural cells. This pathological pattern also seen in asymptomatic smokers. However, in COPD, inflammatory response is amplified many times, especially during exacerbations. Smoke and other irritants on airway activate macrophage, epithelial cells to release the intermediate chemicals. Chemokines play the key role in chronic inflammatory processes of COPD.