Objective　To study the anatomic features of dorsal interosseous nerve and its muscular branches and to provide morphological basis for positioning surface positioning.　Methods　60 dorsal interosseous nerves and its muscular branches from 30  embalmed arm specimens of adult cadavers were dissected. The courses and the bifurcation points of dorsal interosseous nerve were explored. The distances from each bifurcation point respectively to the latera humeral epicondyle(LHE), the Lister's tubercle of the radius (LTR) and the styloid process of ulna (SPU) were measured. The surface position of dorsal interosseous nerve was determined by the “three circle intersection localization method” and “nerve segmentation method”.   Results  There were 4 main bifurcation points of the nerve trunk after dorsal interosseous nerve sent out extensor digitorum branch, extensor digiti minimi branch， and extensor carpi ulnaris branch. The 4 bifurcation points were named O,O1,O2 and O3. Three points, i.e, LHE, LTR and SPT were taken as the center of a circle，and the distance from the bifurcation point to the three points as the radius to draw three circles. The intersection points or regions can be used as the surface location of the nerve. Dorsal interosseous nerve was divided into 7 segments, which were segment above O, segment between O and O1, segment below O1, segment between O and O2, segment below O2, segment between O2 and O3, and segment below O3.    Conclusion    According to the clinical manifestation of dorsal interosseous nerve injury and bifurcation point combined with “three circle intersection localization method” and “nerve segmentation method”, the location of nerve injury could be identified.