The twelve meridians are the main twelve meridians among the meridians and collaterals of the human body, including by the lung meridian of hand-taiyin, the large intestine of hand-yangming, the stomach meridian, the spleen meridian of foot-taiyin, the heart meridian of hand-shaoyin, the small intestine meridian of hand-taiyang, the bladder meridian of foot-taiyang, the kidney meridian of foot-shaoyin, the pericardium meridian of hand-jueyin, the triple energizer meridian of hand-shaoyang, the gallbladder meridian of hand-shaoyang and the liver meridian of foot-jueyin. These 12 meridians are connecting to special internal organs and acupoint and distributed in the head, breast, back, abdomen as well as the four limbs. They are named in accordance to the organs they are connecting to, the character of yin-yang and their location. The branches of the 12 meridians are called as collaterals, whose sub-branches are named as tertiary collateral vessels. The twelve meridians are connecting with each other in order, forming an annular passageway in which the qi and blood circulate for the body health conditions.

The twelve collaterals are the branches of the 12 main meridians, forking from the upper sections of knee and elbow joints and floating along the main collaterals distributed in the head and the entrails. The collaterals of yang meridians go up to the head and then return to the predominant meridians which they are attached. Such a net-work enforces the circulating of blood and qi. Some collateral connect with meridians in internal and external relation and become their gangway; a minority of the collaterals distribute in some viscera and regions far away from their main meridians, which widens the qi circulation areas. However, different from the yang meridians, the collaterals of the yin meridians will not return to their main meridians, but get to the junctures with Meridians in internal and external relation, making up of the setback routine of the qi current, which will regulate Meridians in internal and external relation.

The fifteen collaterals refer to the main collaterals derived from the fourteen meridians and together with the great collateral of the spleen, fifteen collateral vessels in all. (In the Twenty-six Nan of Nan Jing, the author made a mistake by taking the yin-yang meridians of govern and conception as yin-yang heel vessels.) The location of the twelve meridians is all around the wrist and ankle arthrosis. Each of the fifteen collaterals has two branches except the bladder meridian of foot-taiyang, the triple energizer meridian of hand-shaoyang and the pericardium meridian of hand-jueyin. The first branch thrills through the musculature and connects with its meridians in internal and external relation, composing the gangway for the circle flowerage of Meridians in internal and external relation. There are no certain rules for distribution of the second branch. Some are located in the hand and foot; some are distributed upwards along the main meridians; some are in certain organs and parts of the body; some are coming to joining the other related collaterals and enlarge the qi circulation range of the main meridians.
Medical books written in past dynasties all describe the twelve meridians, the twelve collaterals and the fifteen collaterals respectively.

No one has introduced the interrelations of meridians and collaterals, entrails and organs according to combining their connections. The general distribution diagram of meridians and collaterals collected in this book is the final conclusion by taking all the records, dissertations and diagrams in Nei Jing, Nan Jing, Jiayi Jing of Acupuncture, The fifty-two Bingfang, The Eleven Meridians on the limbs for acupuncture, The Eleven Yin-yang Meridians for Acupuncture and Mai Jing into consideration. It also adds some complementarily to these old books. Such as stomach meridian, "great collateral vessel of stomach that impenetrate midriff , collaterals and lung" and "getting through collateral of brain from eye connector" , small intestine meridian of hand-taiyang and large intestine meridian of hand-yangming connect with stomach meridian at crura, kidney meridian of foot-shaoyin is at hallux toe, embranchment of liver meridian distributes over middle energizer, Huiyang acupoint belongs to divergent collaterals of governor vessel and Jingmen,Riyue acupoints belongs to divergent collaterals of gallbladder meridian and so on, which are not recorded in Nei Jing, Jing Mai .This distribution illustration will add some contents according to concerned chapters of Nei Jing.

According to records , The fifty-two Bingfang, The Eleven Meridians on the limbs for acupuncture that lung meridian of hand-taiyin overpasses heart, A-B Classic of Acupuncture and Moxibustion and Illustration of Meridians and Collaterals in past dynasties about flowing route of spleen meridian of foot-taiyin and liver meridian of foot-jueyin in body surface of chest and abdomen, which are brought into diagram to add the absent of Nei Jing, Jing Mai. As distribution route of viscera and bowels and organs in meridians circulation which are recorded in literature of ancient medicine will be expressed in the form of several small branches according to distribution principles of meridian, collateral, tertiary collateral.

Besides, gallbladder meridian is eudipleural, how its left side circuitry reaches liver and gallbladder on the right side, heart meridian of hand-shaoyin circuitry of both sides are distributed over heart and distributed over small intestine from heart below, is it one circuitry or two? Triple energizer meridian of hand-shaoyang is distributed over triple energizers, how to establish the position of triple energizers and so on. This distribution illustration will be protracted according to records of dissection position in Chinese medicine and circulation disciplinarian of meridian and collateral and integrating with modern anatomy.