[A preliminary discussion on the contents and value of Shi er mai (Twelve Channels) and Bie mai (Allo-channels), the medical bamboo slips unearthed from Han tomb in Laoguanshan of Chengdu]

The 52 medical bamboo slips entitled Si er ma (Twelve Channels) and Bie mai (Allo-channels) , unearthed from Han tomb in Laoguanshan, are the exclusive medical books concerning channels. Shi er mai is the first work bearing the term " heart dominating channel" , and the running pathways and manifestations of 12 channels. This book could be the major original sources of the 12-channel theories described in the Chapter of Jing mai (Channels) of Ling shu (Miraculous Pivot) . While Bie mai suggests the coexistence of the multi-channel systems at the time when the book was compiled and, together with the 12 "channel" , and 3 "branched collaterals" , these 2 books represent the original condition before the establishment of the mode of channel circulation in Ling shu, and is significant to explore the nature and origin of channel.