Subcolateral of gallbladder meridian is diverged from Yangfu acupoint of gallbladder meridian and floats along main meridian to anterior aspect of lateral malleolus then separates and runs obliquely to back of the foot and joins its meridian in internal and external relation-liver meridian. When there is disease in subcolateral of gallbladder meridian, it will be pain in waist as hammering and appear obvious puffiness, the symptom can be treated by acupuncture on this vessel.

According to the original context it is at tip of lower end of fibula which is above lateral malleolus, position of subcolateral of gallbladder meridian is clear. Acupoint of tip of lower end of fibula is Yangfu acupoint where gallbladder meridian passes. There is record of Yangfu in A-B Classic of Acupuncture and Moxibustion, so subcolateral of gallbladder meridian should be collateral that diverges from Yangfu acupoint of gallbladder meridian, it floats along gallbladder meridian to anterior aspect of lateral malleolus and separates then descends to back of the foot and joins liver meridian.