Based on ancient and modern literatures of TCM and clinical observation, this paper offers a concept of “taking dryness and dampness as the principle” and detailedly illuminates the specific application in the treatment of chronic cough from the aspect of argument, ways of syndrome differentiation (such as identifying between dryness and dampness, identifying between deficiency and excess, identifying among pathogenic factors, and determining location of disease), and selecting prescriptions and using medicines. It may provide beneficial ways and reference for the treatment of chronic cough with Chinese medicine.