The term meridian is not strange to us． Anyone who has read a gongfu story or seen a gongfu film will be quite familiar with the term， for neither Master Yang Guo nor Master Li Mochou could not have acquired the unparalleled martial arts without“the meridian”．

No doubt the term meridian（Jing－Luo） originated in TCM． Jing means the route or path, and Luo means the network. Just as roads and waterways link each city and village，the meridian， which is distributed throughout the body, connects all Zang－Fu organs，tissues and other organs， and QI and the blood carrying nutrients and messages circulateinside it． Therefore， the meridian is a channel system along which QI and the blood circulate and through which Zall－Fu， limbs and joints are connected and the exterior ,interior, superior and inferior parts of the body communicate with one another．

The meridian system consists of meridians（jing） and collaterals（Luo） as well as 12tendon systems and 12 skin regions． The meridians are divided into 12 main meridians and8 extraordinary meridians， while the collaterals can be further divided into 15 collaterals and numerous fine collaterals and superficial collaterals． The 12 main meridians are the principal course for QI and the blood to circulate along． The 8 extraordinary meridians，different from 12 main meridians， are other important meridians and have the junction of governing， connecting and regulating 12 main meridians． The 12 branch meridians are themeridian branches parting from 12 main meridians with the function of enhancing the cooperation between each exteriorly－interiorly－related pair of the 12 main meridians． The15 collaterals are the general term for the large collaterals that branch out from 12 main meridians， Ren Mai， Du Mai and the spleen， and their functions are to strengthen the connection between two interiorly－exteriorly－related meridians in the body surface and to help QI and the blood to permeate． The superficial collaterals are the collaterals that can be seen though the skin．The fine collaterals refer to numerous tiny collaterals．The 12 tendon systems are the part of the meridian system through which the 12 main meridians connect with muscles and joints and link the four limbs and the bones so as to control the movements of joints The 12 skin regions are the areas of the body surface where the functional activities of the 12 main meridians are manifested

Twelve main meridians are symmetrically distributed on both sides of the body； each main meridian travels along either the medial or the dorsal aspect of the arms or legs and belongs to one of the Zang－Fu organs． Because of these features， the name of each main meridian includes three parts: hand or foot, Yin or Yang, and Zang or Fu. The meridians that pass through the arm are called hand meridians, those meridians travelling through the leg are named foot meridians. Yin meridians, each of which belongs to one of the Zang organs, refer to those meridians that go along the medial side of the arms or legs, while Yan meridians are the ones that run along the dorsal side of the limbs and belong to one of the Fu organs each.