The purpose of the present study were to disclose whether the depth of the mandibular antegonial notch can be used as an indicator of mandibular growth potential. The patients composed of 76 samples and were classified following 3 groups, based on the depth of mandibular antegonial notch: Deep notch group (more than 3mm), Neutral notch group (1-3mm), Shallow notch group (less than 1mm). For each case, the first lateral cephalograms were taken prior to the start of treatment and the second films 3-4 years after. The results were as follows; 1. Deep notch group had a shorter corpus, less ramus height and greater gonial angle than did Shallow notch group. 2. Deep notch group had a more retrusive mandibular position than Shallow notch group. 3. Deep notch group had longer total anterior facial height and longer anterior lower facial height group. 4. Deep notch group grow vertical clockwise growth pattern, while Shallow notch group grow horizontal counterclockwise growth pattern. 5. Deep notch group had less mandibular growth than Shallow notch group during observation period.