The study of qi and blood theory has always been the focus of basic theoretical research in traditional Chinese medicine（TCM）. The disharmony of qi and blood is the pathological reaction of zang-fu organs disorders

and it is also the basic pathogenesis of many diseases. In the process of interaction between qi and blood

the "vessel" plays an important role of intermediary or link. The generation and movement of qi depend on blood

and qi and blood are interacted in the vessel. The vessel is the channel of qi and blood movement

and the intermediary of qi and blood interaction. Therefore

the theory of "qi and blood interacting in the vessel" is proposed

which is interpreted as "qi governs blood by the vessel"

"blood carries qi with the vessel". In addition

the "vessel" is used as a combination of research of TCM qi and blood theory and the research of cardiovascular and cerebrovascular disease to further explore the TCM theory of qi and blood. Taking qi deficiency and blood stasis syndrome as an example

the relationship between the pathological mechanism of cardiovascular and cerebrovascular diseases and the disharmony of qi and blood was clarified

deepening understanding of qi deficiency and blood stasis syndrome

"qi deficiency in the vessel is blood stasis

blood stagnation in the vessel is qi deficiency

qi and blood interacting in the vessel. The above three are mutually cause and result".