This study is a multicenter, prospective cohort study of patients diagnosed with cystic fibrosis, the clinical information of recruited patients, including clinical manifestations, lung function, chest imaging, quality of life and other indicators, will be followed for 10 years.

All new cases of cystic fibrosis which was confirmed or probably diagnosed at each center from the beginning of the study are made the investigation of the clinical manifestations, sweat test and CFTR mutations by the standard diagnostic process.Then all the patients' following clinical data will be followed for 10 years (once per six month): clinical manifestations, lung function, chest imaging (once per year), quality of life and other indicators.

Inclusion Criteria:

• Age 0~18 years old
• Any organ system symptoms consistent with CF, such as chronic sinopulmonary disease, gastrointestinal and nutritional abnormalities, obstructive azoospermia or having siblings with CF
• CFTR dysfunction indicated by elevated sweat chloride levels ≥60 mmol/L twice, or one sweat chloride levels ≥40 mmol/L plus presence of two pathogenic CFTR mutations on different alleles
• Probable CF patients with sweat chloride levels among 40~59 mmol/L plus with presence of 0-1 pathogenic CFTR mutation
• Consent to provide the related clinical specimen to the certain hospital
• The guardians of the patients fully understand the purpose of the study, volunteer their children to participate in this study and sign informed consent.

Exclusion Criteria:

• Subject will be excluded if she or he has one of the following:
• It is unable to provide complete medical records or the current condition can not accept the diagnosis process.
• She or he does not agree to participate in the test.

Children who was confirmed diagnosis as cystic fibrosis at the certain hospitals (sponsor and collaborators)