Abstract: Objective　To explore the morphological characteristics of the dorsal perforators from the palmar artery at the site between the thumb and the index finger, and provide the anatomical basis for the design of the dorsal perforator flap based on the palmar artery.　Methods　Thirty adult upper limb specimens injected with red latex were dissociated to observe the following contents by means of vascular cast and macro-micro-anatomy: ①The origin, courses and distribution of the dorsal nutrient vessels at the site between the thumb and the index finger; ②The anastomotic characteristics of the dorsal perforators of the palmar artery and the dorsal vessels at the site between the thumb and the index finger. One fresh specimen perfused with red latex was performed as a mimic operation.　Results　The blood supply at the site between the thumb and the index finger was multi-sources, which was provided by the dorsal perforators from the palmar artery (the radial palmar digital artery of the index finger and the ulnar palmar digital artery of the thumb) and the branches from the dorsal artery (the first dorsal metacarpal artery). ①The first dorsal metacarpal artery constantly originated from the radial artery and ran in the first metacarpal bone interval, and finally divided into three terminal branches: radial branch, ulnar branch, and intermediate branch，accompanied with homonymous dorsal digital cutaneous nerve from the superficial branch of radial nerve. ②The palmar artery sent out the radial, ulnar, and intermediate perforators towards the dorsum, which formed constant anastomosis with the branches of the first dorsal metacarpal artery to nourish the dorsal skin.　Conclusions　The dorsal perforator flap based on the palmar artery at the site between the thumb and the index finger possessed cross regional blood supply and could be transposed to repair the defects in the proximal part of the index finger, the thenar region, as well as the thumb.

Key words: The radial palmar digital artery of the index finger, 　The ulnar palmar digital artery of the thumb, 　The first dorsal metacarpal artery, 　Perforator flap, 　Site between the thumb and the index finger