The present invention provides an inhalable pharmaceutical composition comprising a glucocorticoid and a polyethylene glycol (PEG)-modified interleukin-2 for treating a respiratory disease. The invention further provides an application of a PEG-modified interleukin-2 for preparing a pharmaceutical composition for enhancing the efficacy of a glucocorticoid in treating the respiratory disease. The invention also provides a method for treating the respiratory disease.
