These are points where two or more meridians intersection, and there are one hundred and one crossing points all over the body. They are mainly distributed on the face, head and trunk; the crossing points on the facial and head regions usually belong to the yang meridians, while the points on the trunk belong to yin meridians. Clinically, the crossing points are often selected when there problem involving multiple meridians. For example, san yin jiao (Sp 6) is an acupoint belongs to the spleen meridian, but the liver meridian and kidney meridian are intersected with the spleen meridian in this location. As a result, this point can be used to treat meridian diseases of the spleen, liver and kidney. Bai hui (GV 20) belongs to the Governor Vessel meridian, however, it is also located at the crossing point of the six yang meridians, thus the point is indicated for problems of all these meridians. San yin jiao (Sp 6)