Abstract： This paper introduces the clinical experience of Professor XIA Xinhua in treating chronic cough and asthma by applying the thought of "if there is no heat，it is cold，and treating the lung without straying from warmth". Professor XIA Xinhua holds that the main pathogenic factor of chronic cough and asthma is cold phlegm. Multiple factors such as environment and diet tend to damage the spleen and stomach， leading to insufficiency of spleen yang， dysfunction in transportation and transformation， and abnormal metabolism of body fluids. The abnormal body fluids then attack the lung upward， resulting in the lung's failure to disperse and descend. Therefore， in modern clinical practice，most patients with chronic cough and asthma present with the syndrome of insufficient lung and spleen as well as phlegm-fluid retention in the lung. On the basis of "treating the lung without straying from warmth" proposed by national traditional Chinese medicine （TCM） master Professor HONG Guangxiang， Professor XIA Xinhua further summarized the TCM pathogenesis and treatment principles of chronic cough and asthma，and put forward the academic thought of "if there is no heat，it is cold" as the theoretical basis for chronic cough and asthma. He guides the treatment of chronic cough and asthma of cold syndrome or mixed cold-heat type with the thought of "if there is no heat，it is cold， and treating the lung without straying from warmth"，using Guizhi Houpo Xingzi Decoction as the basic prescription and modifying it according to symptoms，which achieves excellent therapeutic effects.