OBJECTIVE: To measure the length and extent of the injured blood vessels in an avulsion amputation model. METHODS: Twenty rabbits were randomly divided into 2 groups. Group A was a sharp amputation group, and group B was an avulsion amputation group. The length and extent of the injured blood vessel was observed with naked eye, operation microscope and electron microscope, and the limbs were replanted. Group A and B were explored at three days and ten days after the replantation respectively. The patency rate and healing process were compared. RESULTS: All the severed ends of vessels in group A were neat with almost the same injured range in the three layers of the vessel wall about 1 mm away from the severed end. The vessels of group B were damaged seriously, the endothelial cells were deleted. The "jumping-like" damage could be observed in the elastic fibers. The injury of 2 to 3 mm away from the normal vessel wall could be observed by operation microscope. CONCLUSION: The damage of avulsion amputation vessels was irregular, 2 to 3 mm or more tissues should be excised under the microscope in the process of operation in order to ensure the healthy intact blood vessel walls.