ABSTRACT
Both clinical practice and basic research of acupuncture have pointed out that acupuncture treatment has specific tissue and cellular targets. In addition to the known fixed tissue targets such as nerves and blood vessels, the author analyzes the biological characteristics of other skin resident cells in the skin and concludes that cutaneous mast cells are the most suitable candidate for the cellular target of acupuncture. A hypothesis of the bionic acupuncture is proposed to explain the biological principles by which the innate immunity and healing system respond to acupuncture. The distribution of mast cells in the human skin is characterized by "approaching to the terminals and gathering at the orifices", and the cell density is highly correlated with the density of acupoints and the micro-acupuncture systems. These evidences all support that mast cells are the mobile target cells for acupuncture, which can explain some clinical phenomena and principles of acupuncture, and suggest mast cells as one of the tissue markers for acupoints.