This study is to evaluate the efficacy and safety of Jin-shui Huan-xian granule for idiopathic pulmonary fibrosis (IPF), establish the treatment scheme, and obtain the high quality clinical evidences.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive and ultimately fatal interstitial lung disease. With worsened dyspnea and an increasing loss of pulmonary function, IPF patients will have very poor quality of life. It has also brought an increasing social-economic burden. Researches show that pirfenidone and nintedanib could be effective to IPF, which were also recommended by the guideline. However, the application has been limited by side effects and high prices. It is urgent to develop other effective treatments and strategies to manage IPF. The investigators' previous studies shown that Jin-shui Huan-xian granule could be effective to IPF.

This is a multicerter, randomized, double-blind, placebo-controlled trial to assess the efficacy of Jin-shui Huan-xian granule in reducinig the acute exacerbations, improving exercise capacity, and delaying the disease progression for IPF. After a 2-week wash-out period, 312 patients will be randomly assigned into treatment or control group for 52-week treatment. The primary outcomes are frequencies of acute exacerbation, 6-minute walking test, and percentage of patients with progression-free survival. The secondary outcomes include pulmonary function, all-cause mortality, clinical symptoms, dyspnea score, and quality of life. Safety will also be evaluated.

Inclusion Criteria:

• A confirmed diagnosis stable IPF.
• Age ranges from 40 years to 85 years.
• TCM Syndrome differentiation meets criteria of pattern of Lung Qi deficiency, yin deficiency and inter heat, and lung-kidney qi deficiency.
• Without participanting in any other trial.
• With signed informed consent.

Exclusion Criteria:

• Pregnant, nursing or may become pregnant women.
• Patients with unconscious, dementia or mental disorders.
• Patients with severe cardiac dysfunction.
• Patients with severe liver and kidney diseases.
• Patients with asthma, bronchiectasis, active pulmonary tuberculosis, pulmonary embolism, chronic obstructive pulmonary disease, chronic respiratory failure or other severe respiratory diseases.
• Patients with tumor after resection, radiotherapy or chemotherapy in the past 5 years.
• Patients with severe neuromuscular disorders, severe arthritis or severe peripheral vascular diseases.
• Patients with long-term bedridden.
• Patients who are allergic to any of the treatment drugs.