This study evaluates the efficiency of ICS(budesonide) combined with LABA (formoterol) and LAMA(tiotropium) in the treatment of acute exacerbation of asthma-chronic obstructive pulmonary overlap. Half of participants will receive budesonide,formoterol and tiotropium in combination, while the other half will receive budesonide and formoterol only.

ACO(asthma-chronic obstructive pulmonary overlap) is a relatively new proposed clinical form of chronic airway disease. Guideline or preferring therapy for ACO is still evolving. Current clinical solution is when ACO presents like asthma, initial treatment will accord to the guideline for asthma , while it presents like COPD, COPD recommendation treatment (not alone ICS,but ICS in addition of LABA with or without LAMA) will be chosen, which are subjective. Although present guidelines has recommended that ACO should be treated with at last two inhalant, but limited date have proven it.

A random controlled trial will be conducted to evaluate the efficiency of ICS(budesonide) combined with LABA (formoterol) and LAMA(tiotropium bromide) in the treatment of acute exacerbation of ACO,compared with the control group receiving tiotropium bromide with formoterol only.

Inclusion Criteria:

• subject has ACO

Exclusion Criteria:

• acute exacerbation of ACO;
• acute infection;
• postbrochodilator FEV1/FVC> 0.7;
• pulmonary complications: bronchiectasis, active tuberculosis, pulmonary fungal disease or lung cancer
• history of other malignant tumor
• with rheumatic diseases;
• with some serious heart, cerebrovascular, liver, kidney or hematopoietic system diseases
• with tachyarrhythmias；
• mental patients;
• with moderate to severe renal insufficiency (creatinine clearance ≤ 50ml / h)
• allergic to the budesonide, formoterol or tiotropium bromide;
• history of acute gastrointestinal bleeding within 3 months;
• with severe angle closure glaucoma patients;
• pregnancy,lactation;
• have participated in other clinical trials in 3 months；
• hospital staff and their relatives