OBJECTIVE: To provide anatomical bases for dorso-ulnar aspect of mid-hand reverse flap. METHODS: After red latex was infused into the arteries of 40 sides of adult cadava upper limbs, the origin, course, branches, distribution and distal anastomosis on the dorsal carpal branch of ulnar arteries were observed. And the mid-hand flap transfer was used to repair two cases of soft tissue defect (ranged 4.5-5.0 cm x 2.0-3.5 cm on ring and little fingers). RESULTS: The dorsal carpal branch begins with ulnar artery (3.9 +/- 1.2) cm above the pisiform with diameter of (1.3 +/- 0.2) mm, and branches off into ascending and descending branches. The descending one is the continuing of dorsal branch, it crosses the ulnar edge of the fifth metecarpal bone and anastomizes with the digital artery of little finger or hypothenar branch of deep palmar (accounted for 70%). While the other ascending branch with the former two branches formed anastomosis accounts for 30%. The two cases got healed in one-stage. The function of fingers recovered after 3-4 month follow-up. CONCLUSION: The reverse flap of dorso-ulnar aspect of mid-hand is available to repair the soft tissue defect on dorsum of hand with neighbor finger.