Qing Fei Xiao Yan Wan had been incorporated into the existing “Chinese Pharmacopoeia”, protected by patents. The manufacturing process of it was scientific and its compatibility was reasonable. It was also shown by clinical trials that the efficacy is exact. Clinical trials and experiment studies had confirmed the efficacy and some mechanism for the treatment of respiratory diseases, which were summaried in this paper. Combined with the experimental results (published in another paper), the other prospect application was further discussed.