Objective To investigate the morphological typing and clinical significance of the distal tibiofibular syndesmosis fibular notch based on CT images.    Methods  According to the inclusion and exclusion ceiteria, the imaging data of patients undergoing ankle joint CT examination were analyzed, and the inferior tibiofibular joint fibula notch was classified according to the morphological characteristics. The measurements included 8 distances. There were 123 males and 102 females, all of whom were Han nationality, aged 18-60 years old.   Results  Retrospectively analyzed the result  of 225 patients from December 2013 to December 2022. The distal tibiofibular syndesmosis fibular notch was divided into four types according to morphological characteristics, C-shaped (50.67%), V-shaped (26.67%), flat-shaped (15.11%) and L-shaped (7.56%). The angle between the anterior and posterior facets of the flat shape (145.56 ± 9.25)° was the largest and the angle between the anterior and posterior facets of the L shape  (125.07 ± 13.54)° was the smallest(P<0.05); the depth of the notch in the flat shape (3.11 ± 0.83) mm was the smallest and in the L shape (4.47±1.11) mm was the largest(P<0.05);The posterior facet length (13.06 ± 3.56) mm and anterior tibiofibular gap (3.83±1.49) mm on left were larger than on the right side (P<0.05); The posterior facet length (13.36 ± 3.46) mm, fibular notch depth (3.93 ± 1.10) mm and vertical distance of tibiofibular overlap (9.10 ± 2.55) mm larger in men than in women (P<0.05).   Conclusion  In this study, the data related to the inferior tibiofibular syndesmosis notch were measured and divided into four types according to the shape. The flat inferior tibiofibular syndesmosis notch is more likely to have chronic ankle instability, and the fibula is more likely to move forward during anatomical reduction. The inferior tibiofibular syndesmosis of L-shaped and C-shaped notches is more prone to posterior displacement of fibula or poor rotation reduction during anatomical reduction.