Interstitial lung diseases (ILD) are a group of diseases affecting the lung interstitium. The lung scarring that occurs in ILD is often irreversible with only mitigating therapy available so far. This study intends to carry out an open, single-armed, phase I/II clinical trial to investigate whether lung stem cells can regenerate damaged lung tissue. During the treatment, lung stem cells will be isolated from patients' own bronchi and expanded in vitro. After careful characterization, cultured cells will be injected directly into the lesion by fiberoptic bronchoscopy. The safety and efficacy of the treatment will be monitored by measuring the key clinical indicators.

Inclusion Criteria:

• Diagnosed with interstitial lung disease
• Clinically stable
• Written informed consent signed

Exclusion Criteria:

• Allergic to cell therapy;
• Patients with serious significant pulmonary infection need anti-infection treatment;
• Patients who has taken amiodarone which may cause pulmonary fibrosis in the past 3 months;
• Patients with malignant tumor in the past 5 years;
• Participated in other clinical trials in the past 3 months;
• Patients with serious heart disease(NYHA class Ⅲ-Ⅳ)
• Pregnant or lactating women;
• The investigator assessed as inappropriate to participate in this clinical trial.