We carried out anatomical research of the second metacarpal dorsal artery on 30 cadaver specimens. We find that the second metacarpal dorsal artery is a branch of the radial artery, and it is a nutrient artery for an axial or retrograde skin flap, similar to the first metacarpal dorsal artery island flap. This island flap is used in 7 patients, and all flaps survived well.