Objective: To study the shape, number and thickness of the tidemark in the adult mandibular condylar cartilage and their relationship with age, sex, and loading. Methods: Fifty healthy mandibular condules form people aged from 19 to 74 were divided into four age groups: 19-30, 31-45, 46-59 and 60-74 years old. After decalcification, serially sagittal sections were made from the lateral, central and medial parts of the condyle. The shape, number and thickness of the tidemark were observed and measured in the anterior, superior and posterior regions of each section. Results: The tidemark only appeared in all of the 46 specimens who were considered mature according to the qualitative criteria. The number of tidemarks had no correlation to age, sex, side (left or right) and loading. There was no difference in the thickness of the tidemark among the age groups and no correlation between the thickness and number, age, or side. The thickness in the load-bearing areas (23.26 ± 9.43 mm) was significantly higher than that in the non-load-bearing areas (8.56 ± 5.83 mm) (P < 0.001). There was a higher tidemark thickness in males than in females (P < 0.05). Conclusion: The tidemark is a distinct marker of the fully mature mandibular condyle, and its thickness is related to the loading of the articular surface.