OBJECTIVE： To investigate the safety and effects of different doses of budesonide combined with ipratropium bromide on rational symptom， lung function and arterial blood gas indexes of patients with acute exacerbation of chronic obstructive pulmonary diseases （AECOPD）. METHODS： 186 AECOPD inpatients were selected and randomly divided into low-dose， medium-dose and high-dose groups， with 61 cases in each group. All groups received routine treatment as ipratropium bromide 500 μg+0.9％ Sodium chloride injection （NS） 2 ml， oral inhalation with oxygen drive atomization nebulizer， oxygen flow rate of 4-5 L/min，15-20 min/time，tid. Low-dose， medium-dose and high-dose group were additionally given Budesonide suspension 0.5， 1.0， 2.0 mg+NS 2 ml respectively， oral inhalation with oxygen drive atomization nebulizer， oxygen flow rate of 4-5 L/min 20 min/time， bid. Patients in 3 groups were treated for 7 days. Pulmonary function， MRC score， arterial blood gas indexes and ADR were compared among 3 groups before treatment， 3 and 7 days after treatment. RESULTS： FEV1％ of 3 groups were significantly improved after treatment； 3 and 7 days after treatment， FEV1％ of high-dose group was higher than that of medium-dose and higher than that of low-dose group， with statistical significance （P＜0.05）. The MRC scales of 3 groups were significantly decreased after treatment； 3 days after treatment， MRC scale of high-dose group was lower than those of medium-dose and lower than that of low-dose group， with statistical significance （P＜0.05）. 7 days after treatment， MRC scales of medium-dose and low-dose groups were lower than that of low-dose group， with statistical significance （P＜0.05）， but there was no statistical significance in MRC scale between high-dose group and medium-dose group after treatment 7 days （P＞0.05）. After treatment， there was statistical significance in PaCO2 and PaO2 among 3 groups （P＜0.05）， and the improvement of high-dose group was better than those of medium-dose and better than that of low-dose group， with statistical significance （P＜0.05）. No severe ADR was found in 3 groups. CONCLUSIONS： Aerosol inhalation of 2.0 mg budesonide combined with ipratropium bromide can effectively improve pulmonary function， rational symptoms and arterial blood gas indexes with good safety.