目的    探讨腹主动脉分叉解剖位置影响因素。  方法    在CT影像下分别观测腹主动脉分叉与L4下缘和正中线垂直距离、在正中矢状面用3种不同方法测量腰椎前凸角度,记录年龄、性别、体重指数(BMI)等。  结果　随着年龄增长，腹主动脉分叉呈现逐渐下降，右侧移动趋势。男性主动脉末端持续下移，而女性65岁后才出现明显下移。腰椎前凸角度、性别、BMI与腹主动脉末端位置无相关性(P>0.05)。腰椎前凸与年龄密切相关(P<0.01)。   结论    腹主动脉末端下降，右移与年龄有关，这些发现对低位阻滞有指导作用。 

Objective　To explore the Influential factors for the position of abdominal aortic bifurcation (AB).    Methods　The vertical distances between AB and the midline, between AB and the inferior margin of L4 vertebra were measured on CT images. Lumbar lordosis angles was measured at median sagittal plane by three different methods. Age of patients, gander and body?mass?index?(BMI) were recorded. Results   With the increasing of age, AB gradually decreased and moved to the right side.  Terminal of aorta in male continued to decline, but in female, there did not show a significant downward shift until the age of 65. There were no correlation  between position of AB and lumbar lordosis, gender, BMI (P>0.05). There was significant correlation  between age and lumbar lordosis (P<0.01).　Conclusions　The descending and rightward end of AB was associated with the age. The findings were helpful for low aorta block.