Chronic Obstructive Pulmonary Disease (COPD) is usually characterized by long-term poor airflow, resulting in chronic pulmonary heart disease, chronic respiratory failure or even death. For COPD patients, pulmonary bronchus structures are damaged and cannot be repaired by recent clinical methods so far. This study intends to carry out a single-centered and non-randomized phase I/II clinical trial with concurrent controls to investigate whether bronchial basal cells can regenerate damaged lung tissue. During the treatment, bronchial basal cells will be isolated from patients' own bronchi and expanded in vitro. After careful characterization, expanded cells will be transplanted autologously into the lesion by fiberoptic bronchoscopy. The safety and efficacy of the treatment will be monitored by measuring the key clinical indicators.

Inclusion Criteria:

• Aged between 40 to 75;
• Diagnosed with COPD according the guideline (a. with symptoms of productive cough, sputum production or shortness of breath; b. with poor airflow as indicated by FEV1<70% predicted value and FEV1/FVC < 0.7 in pulmonary function test; c. with exclusion of other pulmonary disease by CT or blood examination.);
• Current smoker or ex-smoker with a history of no less than 10 years or 10 packs/year;
• Tolerant to bronchofiberscope;
• Written informed consent signed.

Exclusion Criteria:

• Pregnant or lactating women;
• Patients positive for syphilis, HIV;
• Patients with malignant tumor;
• Patients with serious significant pulmonary infection and need anti-infection treatment;
• Patients with serious heart disease(NYHA class Ⅲ-Ⅳ);
• Patients with a history of abusing alcohol and illicit drug;
• Patients participated in other clinical trials in the past 3 months;
• Patients assessed as inappropriate to participate in this clinical trial by investigator.