On the connotation of “water” in the theory of traditional Chinese medicine(TCM)，since ancient times it is not clearly defined，so the author reviewed and summarized the ancient literature of TCM.The connotation of “water” at different levels and different category was clarified.based on this the distinction and definition of the connotation of “water，dampness，phlegm，morbid fluid” which is pathological product of water metabolism was completed.At the same time the “Huang Di Nei Jing”，“Shang Han Za Bing Lun”，“Jin Kui Yao Lue” as the starting point，the subtypes and characteristics of “water，dampness，phlegm，morbid fluid” was mainly introduced respectively; and then the author elaborated treatment methods and principles of the “water，dampness，phlegm，morbid fluid” in simple language to explain profound theories.It is expected that the correct understanding of the connotation of “the water of traditional Chinese medicine” is deepen，which will help to improve its theoretical research and guide clinical application.