[The reflection on meridian-collateral theory research].

As the theoretical core of acupuncture and moxibustion of traditional Chinese medicine, the meridian-collateral theory is an original medical theory unique to China, which embodies the wisdom of ancient Chinese medicine practitioners. The meridian-collateral phenomenon is the stepping-stone to success of meridian research, and most of its research ideas are based on finding a pipeline system along the meridian. Due to the fact that the anatomical basis of meridians has still not been made clear, there are many meridian-collateral phenomena reported, but they generally have many problems such as low occurrence rate, poor repeatability, poor specificity, and lack of clear effects of acupuncture, resulting in many controversies in the study. It is well-known that "the meridians connect with the <i>Zang</i>- and <i>Fu</i>-organs in the interior and the four limbs in the exterior", implying the specific relationship between the meridians, body surface (somatic part) and the internal organs, which plays an important guiding role in the selection of acupoints along meridians and the differentiation of meridians in clinical practice, being the core and value of the meridian-collateral theory. The interconnection between different somatic parts of the body is a universal biological phenomenon, and the relationship between the somatic and somatic parts, and between the somatic part and internal organs has also been extensively expounded in modern medicine. If these research results are introduced into the study of meridians, it will further enrich, perfect and develop the theory of meridian-collaterals.