The invention discloses a pharmaceutical composition for treating asthma and chronic obstructive pulmonary diseases (COPD) which contains the following mixed substances: a first active ingredient indacaterol, or pharmaceutically acceptable salt or solvate thereof, or solvate of the salt; and a second active ingredient ciclesonide; wherein, the mol ratio of the first active ingredient to the second active ingredient is 1:15 to 10:1. The composition is applied to treating asthma, chronic obstructive pulmonary diseases, etc. When the lung function is compared with a base value, the ciclesonide and the indacaterol after being combined to treat has more obvious curative effect than any one to treat. The composition is convenient to take, improves compliance of patients, and obviously improves life quality of patients.