The purpose for this study is to determine safety and effectiveness of the oxyhydrogen generator with nebulizer through an adjuvant therapy for the severe COPD patients in the stable phase.

In this study, severe COPD patients in stable phase who were included in both treatment and control groups, administered randomly oxyhydrogen generator with nebulizer (treatment group) or oxygen Nebulizer Machine （control group ）for adjuvant therapy. The therapeutic outcomes in both treatment and control groups are analyzed and evaluated to verify safety and effectiveness of the test product.This study is a multi-center, randomized, double-blind study. The trial lasted for 3 months. The curative effect was observed for subjects in the second week, first month, second month and third month respectively as the observing time point. Total patients which are planned to be included are 140 cases, where, 70 cases in the treatment group and control group respectively are distributed in 5 clinical hospitals.

Inclusion Criteria:

1. It conforms to the diagnostic criteria of chronic obstructive pulmonary diseases (COPD): (PFT)The percentage of forced expiratory volume in forced vital capacity in one second after inhaling vasodilator (FEV1 / FVC% < 70%);
2. Classification of COPD severity by pulmonary function: The criterion for this study is Severe: FEV1/FVC<0.70, and FEV1< 50% expected value after pulmonary function was examined by taking bronchodilator.
3. More than 40 years old and have normal ability to judge independently; men and women are not limited;
4. Living in the vicinity of the test centre in the past six months; -

Exclusion Criteria:

• 1) Those who have acute exacerbation in the past 4 weeks; 2) Lung disease history: Excluding the history of other lung diseases except combined COPD, such as combined pulmonary tuberculosis and diffuse pan-capillary bronchiolitis, pneumonia, pneumothorax, pleural effusion, pulmonary embolism, etc.

  3) Those who suffer infectious diseases such as hepatitis A, hepatitis B, AIDS and tuberculosis or connective tissue diseases in the active period; 4) Those who suffer high fever, as well as various local or systemic infections (including respiratory, urinary and reproductive system, digestive system, sepsis, etc.), severe infection, especially lung infection found by CT examination; 5) Those who have limited ability to understand and poor compliance; do not have the legal capacity or limited legal capacity; participated in other clinical trials in the first 3 months when they were included in the groups; mental or physical disability; 6) Those who were difficult to make an exact evaluation on safety and effectiveness of products; 7) The women in pregnancy and lactation, as well as the women at childbearing age who don't agree to take effective contraceptive measures during the study period; 8) Those who have abnormal heart function and thrombophlebitis; 9) Those who are known and can't stand the oxygen and hydrogen inhalation; 10) Those who are suffered from primary diseases in important visceral organs and systems, such as stroke, severe hypertension, gastric ulcer, uncontrolled diabetes, malignant tumor, liver and kidney failure, and severe heart disease history (acute myocardial infarction, congestive heart failure and other heart diseases in the acute phase); 11) Cancer in progressive stage as well as undetermined masses found in the treatment; 12) Those who have one or more lobectomy history; 13) Those who are suspected to have or really have alcohol and drug abuse history; 14) Those whose AST and ALT≥120U/L, Ccr≤50ml/min; who have shock or unstable hemodynamics; 15) Those who are considered not to participate in clinical trials by the investigators.

the main evaluation index and the secondary evaluation index of all participants will be share in 3 months after the end of this study.