目的　为扩大足背外侧岛状皮瓣的手术方式提供解剖学依据。  方法　33侧成尸下肢标本，经动脉灌注红色乳胶后在手术显微镜下(×10)解剖，观测足背外侧动脉链与足底外侧动脉的吻合及吻合弓的位置，外径，长度。  结果    足背外侧动脉链与足底外侧动脉有3个较恒定的吻合。跗外侧动脉在第5跖骨粗隆后缘发出1条动脉与足底外侧动脉的吻合，命名为足外缘第1动脉弓，起点外径(0.7±0.1)　mm，占54.5%(18侧)；外踝后动脉跟外侧支与足底外侧动脉在外踝前缘下方和外踝后缘下方有2个吻合支，命名为足外缘第2动脉弓和足外缘第3动脉弓，起点外径分别为(0.9±0.1)mm和 (1.0±0.2)mm，分别占　88.0%（29侧）和78.8%（26侧）。  结论　以足外缘动脉弓为蒂的足背外侧岛状皮瓣可修复足底外侧，跟外侧的皮肤缺损。

Objective　To provide anatomical basis for expanding the operation mode of lateral dorsal island flap.    Methods    The anatomic study was carried out on 33 sides of adult cadaveric lower limbs perfused with red latex. With the help of an operation microscope (×10 ) , anastomosis of the lateral dorsal artery and the lateral plantar artery was observed. Finally, we measured the location, diameter, length of the lateral foot vascular arch.    Results　The lateral dorsal artery and the lateral plantar artery had three constant anastomoses from the dorsal to the plantal aspect. The lateral tarsal artery issued a branch at the tuberosity of fifth metatarsal bone, which anastomoses with the lateral plantar artery and was named the first branch of lateral foot artery arch with an external diameter of (0.7±0.1) mm. Its occurrence rat was 54.5%. Two relatively constant anastomoses of the lateral calcaneal artery and the lateral plantar artery were named the second branch of the lateral foot arterial arch and the third branch of lateral foot arterial arch, respectively. The diameter was (0.9±0.1 ) mm and (1.0±0.2) mm，and the occurrence rate were 88.0% and 78.8%, respectively.   Conclusion   The lateral dorsal island flap pedicled with the lateral foot vascular arch is a nideal skin flap to repair the skin defects on the lateral plantar and  lateral calcaneus .