目的：为加深对腓骨下段的认识及其合理应用提供解剖学依据。方法：在73根干燥完整成人标本上（左42，右31）对腓骨全长及其下段进行观测。结果：腓骨全长为（34.1±2.5）cm，其前缘分叉点和下段内侧面三角粗隆顶端至外踝尖的距离分别为（8.5±1.2）cm和（5.9±0.8）cm。外踝的外倾角为（153.1±　5.7）°。结论：(1)从腓骨下1/4段的结构特点上考虑似可将之视为广义上的外踝，该段骨质缺损极难以获得满意的修复；(2)作为供区，腓骨瓣下界不应超越其下1/4段。（3）腓骨瓣切取后期常引发外踝上移，尤其对儿童有较大影响；(4)经腓骨下段入路行踝关节融合术具有方法简便，效果可靠等优点。

        Objective: To deepen the anatomical understanding on distal fibula and offer the reasonable evidences for clinical application. Methods: The morphologic features of the full length of fibula, emphasized on the distal one fourth, were studied and measured on 73 adult dry specimens of fibula (left 42, right 31). Results: The average full length of fibula was about（34.1±2.5）cm. The length from the bifurcate point on distal anterior border and the triangle tuberosity on distal medial surface to the tip of lateral malleolus were （8.5±1.2）cm and (5.9±0.8）cm respectively. The extraversion angle of the articular surface of lateral malleolus was （153.1±5.7）°.  Conclusions: (1) The bone architectues and their distinctive changes on distal 1/4 of fibula would give us a belief that the distal 1/4 of fibula could be defined as the lateral malleolus from broad definition. The bone defect on this segment is hard to be satisfactorily restored. (2) The harvested boundary of fibular flap should not be extended to the distal quarter.（3）The proximal migration of lateral malleolus is often observed on long term follow-up cases, especially in children. (4) The trans-fibular approach for ankle fusion is a convenient and reliable method.