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.