Abstract: Objective　To provide more accurate anatomical data for perioral island flap.　Methods　Sixty-three cast specimens were utilized to observe the origin, distribution, variation and arterial architecture characteristics of the perioral artery.　Results　The mainly blood supply of perioral region came from the superior labial artery, inferior labial artery, labiomental artery and submental artery ascending branch. The superior labial artery mainly originated from facial artery superior (68.25%) or inferior (22.22%) to corner the mouth, the distribution of them were symmetrical (51.59%) or asymmetrical (46.83%), occasionally absence (1.59%). Inferior labial artery mainly originated from facial artery superior to border of mandible (43.65%) or inferior to corner the mouth (28.89%), and formed one branch of facial artery (61.90%) or the final branch (25.40%). The distribution of them were symmetrical (44.44%) or asymmetrical (47.62%), sometimes absence (7.94%). The upper and lower labial arteries anastomosed with each other on both sides, forming an arterial circle around oral fissure, nourishing the oral fissure, nasal region and chin regions. The labiomental artery originated from the facial artery near the mandibular margin, which was mainly 1 branch (about 55%) or absent (about 30%) on each side, but also was 2 branches (about 10%) or 3 branches (about 5%). The submental artery sent out 2~12 ascending branches in the middle submental region, and formed the labiomental vascular plexus with the descending branches of the inferior labial artery and the labiomental artery, nourishing the skin of mental region.　Conclusions　There are many blood supply sources and abundant anastomosis in perioral area, forming an arterial circle and network around the mouth. However, the variation of origin and distribution of the perioral artery are frequent, and the form of artery construction is uncertain. Therefore, it is essential to perform preoperative ultrasonographic exploration before cutting the perioral island flap.

Key words: Superior and inferior labial arteries, 　Perioral island flaps, 　Microsurgical anatomy, 　Arterial casting