The thought of inter-relationship between Lung and Kidney is an important component of visceral manifestation doctrine, and play a role in understanding disease and syndrome types, especially respiratory diseases. Along with development of sciences of physiology, pathology, immunology and molecular biology, the material basis and scientific connotation of inter-relationship of Lung and Kidney have been interpreted and enriched. From basic research and clinical point of view, this paper discussed the life science connotation of inter-relationship of Lung and Kidney and its application condition. All these years of work show that the theory of inter-relationship of Lung and Kidney has rich life science connotation and good clinical application, promoting development of the traditional Chinese medicine and modern life science.